It appears that the Workplace Safety and Insurance Appeals Tribunal (the Tribunal) has once again gained the status of “invincible” after a recent Ontario Court of Appeal decision determined that Ontario courts should respect the authority and validity of findings made by the Tribunal. Essentially, this means that all those with matters before the Tribunal can count on their decisions as being final. On June 3, 2008, the Ontario Court of Appeal released its decision in Mills v. Ontario, setting aside the ruling of the Divisional Court and reinstating the decision of the Tribunal which denied workers compensation benefits to the worker. In arriving at its decision, the Court applied the recent ruling of the Supreme Court of Canada in Dunsmuir v. New Brunswick, which determined that there should now only be two standards of review – correctness and reasonableness. This was only the third time that the Court of Appeal has cited this decision.


In 1979, the worker injured his back while unloading a freezer from a truck during the course of his employment at a dairy. He filed a workers’ compensation claim and was off work for two weeks. He continued to work for the same employer until 1988, until he was laid off. The worker then worked in a grocery store until 1990. Between 1979 and 1990 there were no records of any back complaints. Between 1990 and 1993 he worked as a truck driver. In 1990 he began treatment for back pain and was referred to an orthopaedic specialist. In 1993 he claimed that his back problems were related to his 1979 work accident. The WSIB denied his benefits and he appealed to the Tribunal.


The Tribunal made a determination that it was unable to establish continuity and compatibility between the worker’s accident in 1979 and his current complaints and the denial of benefits was upheld. The worker then applied for judicial review, and appeared before the Divisional Court in 2006. The Divisional Court determined that the Tribunal had made several small errors in fact-finding and that the cumulative effects of these errors resulted in a patently unreasonable decision by the Tribunal. Accordingly, the Divisional Court held that the worker should be allowed benefits for his ongoing injury.


The Court of Appeal was required to determine whether the Divisional Court erred in setting aside the decision of the Tribunal.


The most significant issue to be decided by the Court of Appeal was the amount of deference that should be given to findings of fact made by the Tribunal. The Court of Appeal suggested that the application of the reasonableness standard requires “a contextual approach to deference where factors such as the decision-making process, the type and expertise of the decision-maker, as well as the nature and complexity of the decision will be taken into account.” In applying this test to the Tribunal, the Court found that, as a minister of the Crown making a decision of public policy, “the range of decisions that will fall within the ambit of reasonableness is very broad” and that the decision of the Tribunal should have been shown great deference. Although “one could well justify reaching a different result than the one reached by the Tribunal”, there was an evidentiary basis for the Tribunal’s finding that there was no history of continuing back problems.

After considering all of the evidence before it, the Court of Appeal determined that neither the reasoning nor the conclusion reached by the Tribunal was unreasonable and that the Divisional Court erred in interfering with the findings of fact made be the Tribunal. The decision of the Tribunal was restored accordingly.

It should be noted that the Divisional Court has also found another Tribunal decision to be patently unreasonable in Rodrigues v. Workplace Safety and Insurance Appeals Tribunal. However, the Court of Appeal has granted the Tribunal leave to appeal the Divisional Court Decision and this appeal will likely be heard in the fall. It will be noteworthy to follow this appeal to see if the Tribunal remains “invincible”