IN THE SUPREME COURT OF BRITISH COLUMBIA
Hill v. WCB,
2007 BCSC 1187
IN THE MATTER of the Judicial Review Procedure
R.S.B.C. 1996, c. 241; and the decision of the
Workers’ Compensation Appeal Tribunal
Rendered on June 21, 2006
Robert Douglas Hill
Compensation Board of British Columbia
and Workers’ Compensation Appeal Tribunal
Before: The Honourable Mr. Justice Butler
Reasons for Judgment
Counsel for Petitioner
Counsel for Respondent Workers’ Compensation Board
Counsel for Respondent Workers’ Compensation Appeal Tribunal
Date and Place of Hearing:
May 28 & 29, 2007
 On February 1, 2005, the petitioner, a bus driver with Coast Mountain Bus Company Ltd., was threatened by a passenger. As a result of the incident, the petitioner was diagnosed as suffering from post-traumatic stress disorder (“PTSD”) and he was unable to return to work for approximately eight months. He applied to the Workers’ Compensation Board of British Columbia (“WCB”) for compensation on February 14, 2005. The claim was denied. The petitioner filed a request for a review, and on August 11, 2005, the review officer confirmed the claim decision on the basis that the petitioner’s PTSD was not an acute reaction to a sudden and unexpected traumatic event. The petitioner appealed that decision to the Workers’ Compensation Appeal Tribunal (“WCAT”). On June 21, 2006, WCAT dismissed the petitioners’ appeal. The petitioner now seeks an order pursuant to the Judicial Review Procedure Act, R.S.B.C. 1996, c. 241, that the decision be set aside and the matter remitted to WCAT for their reconsideration.
 The petitioner is 56 years old and has been employed as a bus driver for approximately 32 years. Over the course of his employment, he has been involved in a number of attacks and confrontations. These include:
(a) in 1991, a fare dispute escalated into a violent assault during which the petitioner was kicked in the head. He suffered serious injuries, including pain, scarring and visual impairment as a result of the attack. He also suffers from sporadic visual flashbacks about the assault;
(b) in 1993, he was grabbed by the neck and choked by a supervisor;
(c) in 2003, he was punched in the jaw by a passenger;
(d) in 2003, he was threatened by teenagers with a machete;
(e) in 2004, an irate motorist spat on the petitioner; and
(f) in November 2004, a passenger struck the petitioner in the shoulder during a fare dispute. The petitioner chased the passenger off the bus, struck him in the leg and attempted to detain him for the police. The passenger was the same individual involved in the February 1, 2005 incident in question. As a result of his actions in attempting to apprehend the passenger, the petitioner was briefly suspended by his employer.
 The February 1, 2005 incident arose from a fare dispute. The passenger boarded the bus and said that he did not have the fare but was going to get his paycheque. The petitioner informed the passenger that the fare was $2.25. The passenger then stepped off the bus and said, “Do you want to settle this now? I’ll knock your f.....g head off”. Transit security was present at the time and the passenger was charged.
 After the February 1, 2005 incident, the petitioner did not feel that he could safely operate a bus. He informed a WCB officer that he was going to grieve the suspension that resulted from the November 2004 incident, and that he was extremely upset at his treatment by the employer with regard to that incident. He also said that the February 1, 2005 incident had brought up all his emotions related to the earlier incident and his treatment by his employer.
 The petitioner received treatment from his family physician, who diagnosed his condition as PTSD. At the request of his disability carrier, an independent medical examination was carried out by Dr. Jeanette Smith, psychiatrist. Her report concluded with the following diagnosis:
Mr. Hill appears to have experienced an episode of major depression with significant anxiety symptoms … . It would appear that his episode of depression was triggered by conflict in his workplace, mainly a threatening episode with a member of the public who had already assaulted him three months earlier. However, it is evident that it was not simply this encounter with a member of the public that triggered his emotional problems, but rather the reaction of his employer which left him feeling angry and unsupported.
 The petitioner was referred to a psychiatrist, Dr. C.I. Melck, by his family doctor. Dr. Melck also formed the opinion that the petitioner suffered from PTSD which, by September 2005, was in partial remission. The PTSD was complicated initially by a major depressive episode. Dr. Melck stated:
Even though the latest episode appears to be relatively minor compared to previous traumatic episodes, it is sensitized by past traumatic events that contributed to the latest incident precipitating the full post-traumatic stress disorder symptoms.
 Compensation for “mental stress” is addressed in s. 5.1 of the Workers Compensation Act, R.S.B.C. 1996, c. 492 (the “Act”):
(1) Subject to subsection (2), a worker is entitled to compensation for mental stress that does not result from any injury for which the worker is otherwise entitled to compensation, only if the mental stress
(a) is an acute reaction to a sudden and unexpected traumatic event arising out of and in the course of the worker’s employment,
(b) is diagnosed by a physician or a psychologist as a mental or physical condition that is described in the most recent American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders at the time of the diagnosis, and
(c) is not caused by a decision of the worker’s employer relating to the worker’s employment, including a decision to change the work to be performed or the working conditions, to discipline the worker or to terminate the worker’s employment.
 Section 82(1)(a) of the Act empowers and directs the board of directors (the “Board”) of the WCB to “set and revise as necessary the policies of the board, including policies respecting compensation, assessment, rehabilitation and occupational health and safety …” Pursuant to that provision, once the Act was amended in 2002 to include s. 5.1 dealing with mental stress claims, the Board adopted policy 13.30 to deal with such claims. Pursuant to ss. 250-251 of the Act, WCAT is required to base its decision upon Board policy. Portions of those sections include:
250 (1) The appeal tribunal may consider all questions of fact and law arising in an appeal, but is not bound by legal precedent.
(2) The appeal tribunal must make its decision based on the merits and justice of the case, but in so doing the appeal tribunal must apply a policy of the board of directors that is applicable in that case.
251 (1) The appeal tribunal may refuse to apply a policy of the board of directors only if the policy is so patently unreasonable that it is not capable of being supported by the Act and its regulations.
 The relevant provisions of policy 13.30 include the following:
A worker may be entitled to compensation for mental stress that does not result from a physical injury or occupational disease if the impairment is due to an acute reaction to a sudden and unexpected traumatic event.
“Mental stress” is intended to describe conditions such as post-traumatic stress disorder or other associated disorders. Mental stress does not include “chronic stress”, which refers to a psychological impairment or condition caused by mental stressors acting over time. Workers, who develop mental stress over the course of time due to general workplace conditions, including workload, are not entitled to compensation.
Under subsection 5.1 (1)(a), the Act establishes a two-part test:
1. There must be an acute reaction to a sudden and unexpected traumatic event.
2. The acute reaction to the traumatic event must arise out of and in the course of employment.
An “acute” reaction means – “coming to crisis quickly”. It is a circumstance of great tension, an extreme degree of stress, it is the opposite of chronic. The reaction is typically immediate and identifiable. The response by the worker is usually one of severe emotional shock, helplessness and/or fear. It may be the result of:
· a direct personal observation of an actual or threatened death or serious injury;
· a threat to one’s physical integrity;
· witnessing an event that involves death or injury; or,
· witnessing a personal assault or other violent criminal act.
For the purposes of this policy, a “traumatic” event is a severely emotionally disturbing event. It may include the following:
· a horrific accident;
· an armed robbery;
· a hostage-taking;
· an actual or threatened physical violence;
· an actual or threatened sexual assault; and,
· a death threat.
In most cases, the worker must have suffered or witnessed the traumatic event first hand. In all cases, the traumatic event must be
· clearly and objectively identifiable; and
· sudden and unexpected in the course of the worker’s employment.
This means that the event can be established by the Board through information or knowledge of the event provided by co-workers, supervisory staff, or others, and is generally accepted as being traumatic. … .
Examples where there is likely entitlement to compensation for mental stress:
· A person commits suicide by jumping in front of a bus.
· A worker directly witnesses a very serious accident to a co-worker.
· During a prison riot, inmates hold a guard hostage.
· A female worker attends at work and is confronted by her male supervisor who sexually assaults her.
 In the decision rejecting the petitioner’s appeal from the review division decision, WCAT accepted that the mental stress diagnosed by the psychiatrists (either PTSD or depression) was a recognized DSM condition, such that the requirement of s. 5.1(1)(b) was met. The issue to be determined was whether or not the mental stress was an acute reaction to a sudden and unexpected traumatic event. After noting that this was a mixed question of law and fact, reference was made to Dr. Melck’s conclusion that the petitioner’s PTSD resulted from a “relatively minor” incident because he had been sensitized by past traumatic events. In deciding that the altercation of February 1, 2005 was not a “sudden and unexpected traumatic event”, WCAT explained its decision as follows:
According to the policy, however, it appears that a worker’s heightened sensitivity is not to be taken into account in determining whether an incident was traumatic - for the purposes of compensation. In that sense, an event must be traumatic from an objective perspective. The policy indicates this through the examples provided which are clearly examples of incidents which any person would view as traumatic. In addition, the policy states, a “traumatic” event is a severely emotional disturbing event that is “generally accepted as traumatic.”
Accordingly, it is not sufficient that the event was severely emotionally disturbing at least partially because of the worker’s history; the event must be one that is generally recognised as traumatic. It must be the sort of event that could precipitate a disorder recognised in the DSM in any person. Although, medically, an event may be viewed as sufficiently traumatic to precipitate a disorder such as PTSD in a particular worker, if the event is not “traumatic” as that term has been defined by the policies, the worker is not entitled to compensation.
Standard of Review
 The parties have each taken the position that the appropriate standard of review is patent unreasonableness. However, I am required to carry out the necessary analysis to determine the standard of review on the pragmatic and functional approach: Speckling v. British Columbia (Workers’ Compensation Board), 2005 BCCA 80.
 The starting point of this analysis is the Administrative Tribunals Act, S.B.C. 2004, c. 45 (the “ATA”). Following enactment of the ATA , consequential amendments were made to the Act (WCAT’s enabling legislation) which provided specifically that s. 8 of the ATA applies to WCAT. Section 58(1) of the ATA provides:
If the tribunal’s enabling Act contains a privative clause, relative to the courts the tribunal must be considered to be an expert tribunal in relation to all matters over which it has exclusive jurisdiction.
 Section 58(2) of the ATA provides:
In a judicial review proceeding relating to expert tribunals under subsection (1)
(a) a finding of fact or law or an exercise of discretion by the tribunal in respect of a matter over which it has exclusive jurisdiction under a privative clause must not be interfered with unless it is patently unreasonable.
 The ATA defines “privative clause” as follows:
“privative clause” means provisions in a tribunal’s enabling Act that give the tribunal exclusive and final jurisdiction to inquire into, hear and decide certain matters and questions and provide that a decision in respect of the matters within its jurisdiction is final and binding and not open to review in any court.
 WCAT’s enabling legislation contains the following privative clause:
255 (1) Any decision or action of the chair or the appeal tribunal under this Part is final and conclusive and is not open to question or review in any court.
 The result of these provisions is that WCAT must be considered an expert tribunal and, accordingly, pursuant to s. 58(2), provided that WCAT has exclusive jurisdiction, the standard of review is patent unreasonableness.
 The determination of entitlement to compensation, including interpreting and applying the Act and Board policy, lies at the heart of the WCB’s function and, on appeal, WCAT’s function on a substitutional basis: ss. 254, 253(1)(i), 250, 239(1), 96.2(1)(a) and 96(1) of the Act. Section 254 of the Act provides:
The appeal tribunal has exclusive jurisdiction to inquire into, hear and determine all those matters and questions of fact, law and discretion arising or required to be determined under this Part and to make any order permitted to be made, including the following:
(a) all appeals from review officers’ decisions as permitted under section 239;
 I conclude that the issue of entitlement that was raised by the appeal to WCAT fell squarely within its exclusive jurisdiction and, thus, s. 58(2) of the ATA. However, if I am incorrect in that conclusion, application of the four factor pragmatic and functional approach as set out in Pushpanathan v. Canada (Minister of Citizenship and Immigration),  1 S.C.R. 982, also leads to the conclusion that this Court should give deference to the WCAT decision and apply the standard of patent unreasonableness. Briefly, my consideration of those factors includes:
a) As noted above, WCAT is covered by a comprehensive privative clause;
b) The courts have accepted the WCB’s expertise in workers’ compensation issues based on the statutory material alone: Kovach v. British Columbia (Workers’ Compensation Board) (1998), 52 B.C.L.R. (3d) 98 (C.A.), rev’d  1 S.C.R. 55. In Pasiechnyk v. Saskatchewan (Workers’ Compensation Board,  2 S.C.R. 890, Mr. Justice Sopinka commented on the nature and scope of the Saskatchewan WCB’s expertise, which also applies to both the WCB and WCAT in British Columbia:
The composition, tenure, and powers of the Board demonstrate that it has very considerable expertise in dealing with all aspects of the workers’ compensation system. Not only does the Board have day-to-day expertise in handling claims for compensation, in setting assessment rates and promoting workplace safety; but it also has expertise in ensuring that the purposes of the Act are not defeated (¶ 38);
c) The nature of the Act
The Act as a whole sets up a comprehensive workers’ compensation scheme. The compensation benefits portion of the Act represents a balancing of interests between the worker and employer constituencies. This is accomplished by means of the provisions of the Act and the underlying policies. The specific policy engaged in this appeal sets out the criteria for determining compensation in a mental stress claim under s. 5.1 of the Act. Both the section and the policy lie at the heart of the WCB’s jurisdiction to determine entitlement to compensation and, thus, WCAT’s exclusive jurisdiction to hear appeals on those issues. Accordingly, this factor also suggests that the Court should give deference to the decision of WCAT; and
d) The nature of the problem
The WCAT decision addresses whether the plaintiff’s condition was in response to a sudden and unexpected traumatic event. It is a question of entitlement which engages the interpretation and application of s. 5.1 and policy 13.30. This is a fact-intensive question of mixed fact and law. The comments of Cromwell J.A. in Canada Post Corp. v. Connolly, 2006 NSCA 3 at ¶ 56, with regard to the Nova Scotia workers’ compensation appeal tribunal, are applicable to the British Columbia WCAT:
While I do not think that, in general, WCAT has markedly greater relative expertise with respect to legal questions arising under the WCA, the tribunal’s specialized functions, in my view, support a measure of deference with respect to certain types of legal questions falling squarely within the tribunal’s specialized functions.
The issue here is whether or not policy 13.30 requires an objective test with respect to the interpretation of what is a “sudden and unexpected traumatic event”. This is the kind of issue that falls within WCAT’s specialised functions and thus supports a measure of deference.
 In summary, all of the factors to be considered in the pragmatic and functional analysis suggest that this Court should give a high level of deference to WCAT. The proper standard of review is patent unreasonableness.
1. Was WCAT’s interpretation of policy 13.30 patently unreasonable?
2. If the answer to Issue (1) is no, is the policy itself patently unreasonable?
3. Was WCAT’s decision that the February 1, 2005 incident was not, objectively, traumatic patently unreasonable?
Issue 1: WCAT’s interpretation of policy 13.30
 The petitioner takes issue with WCAT’s conclusion that before the worker can be entitled to compensation for mental stress, the event that precipitated the condition “must be one that is generally recognized as traumatic. It must be the sort of event that could precipitate a disorder recognized in the DSM in a person.” The petitioner notes that the Act itself does not require that the event be “generally recognised as traumatic”, only that the worker’s condition be “an acute reaction to a sudden and unexpected traumatic event arising out of and in the course of the worker’s employment.” Further, the petitioner says that while the policy does state that the event must be one that “is generally accepted as being traumatic”, that passage only applies to the identification of the event itself.
 In support of that position, the petitioner refers to Logan v. Nova Scotia (Workers’ Compensation Appeals Tribunal), 2006 NSCA 88. In that case, the Court was considering whether a wrongful dismissal of an employee that caused mental stress could constitute an accident. The Nova Scotia Act provided that “accident” did not “include stress other than an acute reaction to a traumatic event”. The Court held in paras. 87-88 that:
There must be an objectively determinable accident which arose out of and in the course of employment. …
In my view, an objective approach to defining “traumatic event” is more in keeping with the overall scheme of the WCA.
 The petitioner argues that the objective approach adopted by the court in Logan relates solely to the identification of the “traumatic event”. Once that event is clearly and objectively identified, the “thin skull rule” applies as it would for any other injury. When that is done, the petitioner says that the condition of the worker is judged subjectively (including whether or not the event was “traumatic”), including consideration of particular susceptibilities or pre-existing conditions.
 The petitioner also seeks support from the decision of the New Brunswick Court of Appeal in D.W. v. New Brunswick (Workplace Health, Safety and Compensation Commission), 2005 NBCA 70. In that case, the court considered a claim for compensation for mental stress arising out of a non-violent confrontation between a worker and a manager. The legislation excluded from the definition of “accident” “disablement caused by mental stress, other than as an acute reaction to a traumatic event”. The court stated as follows at para. 51:
The question properly formulated is whether the reasonable person would regard the precipitous event as a traumatic one (out of the usual, expected or ordinary) because it is the type of occurrence that could realistically result in an employee being unable to continue with his or her employment.
 The petitioner argues that the objective approach as set out in Logan and D.W. asks whether “a reasonable person would regard the incident in question as one that could realistically or possibly lead to a psychological injury that would prevent the employee from continuing with his work.” The petitioner says that this is very different from the objective approach applied by WCAT in this case. The petitioner says that the question asked by WCAT - was the incident “the sort of event that precipitates a disorder recognised in the DSM in any person” - is a question that is impossible to answer. It requires a quantative assessment of the event; in other words, is it an event that is sufficiently traumatic to precipitate a disorder in anyone?
 WCAT’s interpretation of the policy would be patently unreasonable if it is not in accord with reason or is clearly irrational: Canada (AG) v. P.S.A.C.,  1 S.C.R. 941. If a defect is apparent on the face of the tribunal’s reasons, then the decision is patently unreasonable, but if it takes some significant searching or testing to find the defect, then the decision is unreasonable, but not patently unreasonable: Canada (Director of Investigation and Research, Competition Act) v. Southam Inc.,  1 S.C.R. 748.
 Further, it is the result which must be tested for patent unreasonableness rather than the reasoning itself. If a rational basis can be found for the decision, it should not be disturbed: Kovach supra, per Donald J.A. at para. 26.
 Here, the interpretation by WCAT of policy 13.30 cannot be said to be patently unreasonable. The word “traumatic” could be interpreted as including a subjective element, but it can also be interpreted objectively. The relevant portions of the policy set out a test with regard to the “traumatic event”. It must be:
(a) clearly and objectively identifiable;
(b) sudden and unexpected in the course of the worker’s employment; and
(c) generally accepted as being “traumatic”.
 This test is somewhat akin to a causation theory because it sets the criteria that must be met before a worker may be entitled to compensation. As noted by Mr. Justice Donald in Kovach, supra, at para. 28, “No single theory of causation can be said to be infallible or universally applicable. What works for a tort based system may be unsuitable for a no fault scheme. It all depends on the policy goals of the system.”
 The policy goals of the workers’ compensation system include the provision of fair compensation to injured workers taking into account the balancing of interests of the various constituencies. When interpreting policy, the issues of triggering events and causative significance must be considered. Here, WCAT has applied an objective test. Other jurisdictions have applied a similar objective test in relation to assessment of the concept of a “traumatic event”. Contrary to the petitioner’s submissions, the interpretation of the policy by WCAT is supported by the decisions in Logan and D.W. As noted by the court in D.W. at para. 51:
In my view, the test for assessing whether an event is traumatic must be an objective one. If it were a purely subjective test or even a modified subjective test, the most innocuous of management decisions could support a claim for psychological injury. It would not be difficult for the skilled advocate to turn a case of “chronic” or “gradual onset” stress into a claim of psychological injury by focusing on a single incident’, the one that broke the camel’s back, so to speak. The overly sensitive employee who is experiencing a severely stressful home or work life might well suffer an acute reaction to a critical management decision.
 The same rationale applies to events that are not management decisions. To paraphrase from D.W., “the most innocuous confrontation with a passenger could support a claim for mental stress.” The choice of an objective test to determine whether or not an event is traumatic is not unreasonable, let alone patently unreasonable. As noted above, this is supported by decisions in other provinces. The history of the development of an interpretation of policy related to mental stress in other provinces is set out in some detail in the D.W. decision.
 In advancing its argument on this issue, the petitioner focused on the WCAT’s comment that the event “must be the sort of event that could precipitate a disorder recognized in the DSM in any person.” This was contrasted with the conclusion in D.W. that proposed a reasonable person test. However, in considering whether or not the interpretation of WCAT was patently unreasonable, it is not helpful to look for defects in the language utilized by the panel.
 There is some merit to the argument that it would be almost impossible to determine whether the event could cause a recognized disorder “in any person”. However, the decision of WCAT can be arrived at by applying the same principle as set out in D.W.; that is by asking if the event would be “generally recognised as traumatic”? In my view, that is all that WCAT was doing in its decision. While its choice of words suggests a more stringent test, when read as a whole, the WCAT reasoning does no more than ask whether or not a reasonable person would regard the incident in question as one that could realistically lead to a psychological injury.
 The petitioner also relies upon Plesner v. British Columbia (Hydro and Power Authority), 2006 BCSC 1947. In that case, Mr. Justice Wong found that where there was medical evidence that the worker had developed a mental condition described in the DSM (PTSD), the WCAT’s decision in that case - that the conclusion of the event was not “generally accepted as traumatic” - amounted to an internal inconsistency. Mr. Justice Wong referred the matter back to the WCAT for reconsideration. In doing so, he stated at para. 5 that “it may well be that the phraseology on the second paragraph (the paragraph that concluded that the event was not traumatic) did not specifically state what the vice chair intended to convey.” The judicial review application in Plesner was raised as a s. 15 Charter issue. Mr. Justice Wong gave his decision orally and without reference to a standard of review or any caselaw. In essence, he invited WCAT to reconsider its decision or explain the rationale for that decision.
 The petitioner here argues that the decision is directly on point and that I must follow it. Rather, I have concluded that the case is distinguishable. What is not clear on the face of the WCAT Plesner decision is the distinction between the medical diagnosis of PTSD on one hand and the legal test for causation or entitlement on the other hand. That distinction is made clear on the face of the WCAT decision in this case:
Dr. Melck, however, has approached the question of what constitutes a traumatic event from a medical perspective, whereas the board officer and the review officer determined whether the incident could be characterized as traumatic, at least on standards established by law and policy. The main difference between these two approaches appears to be whether the history and particular sensitivities of the individuals are taken into account in deciding whether there has been a traumatic event.
 In the present case, there is no apparent inconsistency in the decision of WCAT. As a result, the issue in this case does not involve an apparent inconsistency in the reasoning of WCAT, but rather the interpretation of the policy, as explained in detail in WCAT’s decision.
Issue 2: Is policy 13.30 patently unreasonable?
 The respondent, WCB, argues that the petitioner should be estopped from raising this issue on the application for judicial review because it was not raised before WCAT. It also argues that the petitioner failed to exhaust the internal remedies provided by s. 251 of the Act, as a result of which this Court should not entertain the argument on this judicial review application.
 The estoppel argument is based upon the decision of the Court of Appeal in Chapman v. Canada; Westwick v. Canada, 2003 BCCA 665. That case bears little similarity to the present case. The plaintiffs pursued a matter through resolution to the Supreme Court of Canada and, when they were unsuccessful, commenced a second action addressing an issue that could have been pursued in the initial action. The Court ruled that the matter was res judicata and that the second action was an abuse of process. That is very different from the circumstances here.
 The suggestion that the petitioner was bound to exhaust its remedies is based upon s. 251, which sets out a process that is to be followed when WCAT considers that the policy of the Board should not be applied because it is not capable of being supported by the Act and regulations. When that occurs, the WCAT chair must determine whether the policy should be applied. If the determination is made that it should not be applied, the chair must then refer it to the Board, which must review the policy. The Board then provides notice to the parties to the WCAT appeal to make written submissions to the Board, as well as to other parties who have appeals pending. Once the Board receives submissions and decides whether or not to change its policy, WCAT is bound by that determination.
 In Western Stevedoring Co. v. British Columbia (Workers’ Compensation Board), 2005 BCSC 1650, Mr. Justice Groberman considered the provisions of s. 251 and found that there was no requirement to exhaust internal remedies where the question at issue was the legality of the WCB policy. Mr. Justice Groberman stated as follows at paras. 41-42:
I am not convinced that the internal review provisions in the Workers Compensation Act furnish an adequate alternative remedy to judicial review where the matter in issue is legality of a policy issued by the board of directors of the Board. Throughout the process, decision- makers are required to defer to the policies of the board of directors. Even where the policies are found to be patently unreasonable, there is no certainty that the decision-makers will be allowed to depart from them.
I am not satisfied that, where the sole issue is the legality of a policy, the grieved party should be required to follow the Act’s lengthy and inconclusive procedures of review and appeal.
 In Western Stevedoring, the applicant for judicial review did not appeal to WCAT. This was because WCAT had already ruled pursuant to s. 251 that the policy was patently unreasonable, but had been directed by the Board to apply the policy. The situation in the present case is somewhat different. However, the comments of Mr. Justice Groberman regarding the adequacy of s. 251 as an alternative remedy apply. Section 251 does not, on its face, purport to be an alternative remedy for the appellant. Rather, it sets out a procedure that WCAT is to follow if it is of the view that the policy is patently unreasonable. Here, WCAT must have concluded that the policy was not patently unreasonable or the policy would not have been followed. The petitioner is, accordingly, not prevented from raising this issue on this application for judicial review.
 The petitioner’s argument with respect to this issue is very similar to its arguments regarding Issue 1. Here, the petitioner says that if the policy itself does call for an objective test of what amounts to a “traumatic event”, then the policy is patently unreasonable because s. 5.1 of the Act does not require that. This argument ignores the ambiguity contained in the term “traumatic event”. As explained in both Logan and D.W., and in other decisions, the phrase could be interpreted subjectively, objectively or perhaps a mixed subjective-objective could be applied. Given the range of possible interpretations, it is difficult to say that the one chosen by the Board is patently unreasonable.
 The decisions that had to be made by the Board in setting the mental stress policy and by WCAT in interpreting that policy are the kind of decisions that lie at the heart of the purpose of the workers’ compensation scheme. The decision as to what kind of event would attract entitlement involves the balancing of interests of the worker and employer constituencies. In Pushpanathan, at para. 36, the Supreme Court of Canada observed that the statutory purpose and expertise often overlap. The purpose of the statute is often reflected in the specialized nature of the legislative structure and dispute settlement mechanisms. The Court also observed that where the “purposes of the statute and of the decision-maker are conceived not primarily in terms of establishing rights as between parties, or as entitlements, but rather as a delicate balancing between different constituencies, then the appropriateness of court supervision diminishes.” (Para 36).
 In National Corn Growers Assn. v. Canada (Import Tribunal), , 2 S.C.R. 1324, the Court recognized the role that bodies like WCB play in resolving ambiguities in statutory language. At para. 10, the Court cited with approval the following statement from J.M. Evans et al., Administrative Law, 3rd ed. (Toronto: Emond Montgomery, 1989) at 414:
In administrative law, judges have also been increasingly willing to concede that the specialist tribunal to which the legislature entrusted primary responsibility for the administration of a particular programme is often better equipped than a reviewing court to resolve the ambiguities and fill the voids in the statutory language. Interpreting a statute in a way promotes effective public policy and administration may depend more upon the understanding and insights of the front-line agency than the limited knowledge, detachment, and modes of reasoning typically associated with courts of law. Administration and interpretation go hand in glove.
 If the petitioner’s argument was accepted, it would take away from WCB the right to determine what kind of an event falls within the statutory language. This would have the effect of taking away from WCB the right to resolve one of the obvious ambiguities in s. 5.1. This is precisely the kind of issue where the WCB has significant expertise.
Issue 3: Was WCAT’s decision that the February
1, 2005 incident
was not objectively traumatic patently unreasonable?
 The petitioner argues that on the undisputed facts he was threatened with physical violence by an individual who had assaulted him just four months earlier. The transit police were called and took the individual into custody. The petitioner also notes that one of the examples given in policy 13.30 for a traumatic event is “an actual or threatened physical violence”.
 The argument has some initial appeal. On its face, this sounds like an event that could be generally considered to be traumatic. However, the determination as to what amounts to the traumatic event must be given the highest level of deference: Children’s Aid Society of Cape Breton - Victoria v. Nova Scotia (Workers’ Compensation Appeals Tribunal), 2005 NSCA 38.
 The kind of findings necessary to determine whether or not an event is traumatic lie at the core of WCAT’s expertise in determining compensation issues under the Act. The difficulty faced by the petitioner here is similar to the one faced by the petitioner in Basura v. British Columbia (Workers’ Compensation Board), 2005 BCSC 407. As the Court stated at para. 34:
The petitioner faces a significant burden in this case. She must show that upon review of the evidence, there is no rationale basis for the conclusion reached by the WCAT. In applying the standard of patent unreasonableness, it is not open to me to re-weigh the evidence and conclude that, on my assessment, the petitioner should have succeeded. In addition, in applying the standard, only the conclusion of the WCAT is open to judicial review.
 Here, the petitioner would have to show that there is no rationale basis for WCAT’s conclusion that the event was not, objectively, “traumatic”. Here, the review officer heard, and the WCAT heard or reconsidered, the evidence. This Court does not sit in the same position.
 There seems little doubt that the event was, to use the language of Dr. Melck, “relatively minor compared to previous traumatic episodes”. The petitioner does not appear to have been in any immediate or imminent personal risk. The evidence was evaluated and it was determined that the event was one that could not, generally, be accepted as being traumatic. The petitioner cannot argue that there are not, in the spectrum of events, some events that a reasonable person would regard as not being traumatic.
 Although I have sympathy for the petitioner, who was diagnosed as suffering from either PTSD or depression following the incident of February 1, 2005, he has not been able to satisfy me that WCAT’s interpretation of policy 13.30 was patently unreasonable. In addition, I do not find that the policy itself was patently unreasonable or that WCAT’s application of the policy was patently unreasonable. The petitioner’s application for judicial review is dismissed.
 Given the circumstances of this case and the fact that neither of the respondents sought costs, the order will be that each party bear its own costs.
B. Butler, J.