Executive Summary: Key Legal and Evidentiary Issues

• The Tribunal excluded workplace exposure evidence from the rebuttal analysis of a statutory presumption without justification.

• The presumption that cancer was caused by firefighting duties could only be rebutted by non-workplace causes, according to the Tribunal’s interpretation.

• The WSIB policy allowed rebuttal based on evidence that employment was not a significant contributing factor, which the Tribunal ignored.

• The Tribunal failed to follow binding Board policy as required under the Workplace Safety and Insurance Act.

• The Divisional Court found the Tribunal’s interpretation unreasonable and inconsistent with the plain language of the statute.

• The Court quashed the Tribunal’s decisions and reinstated the Board’s original denial of benefits.

Facts of the case

The City of Toronto sought judicial review of a series of decisions made by the Workplace Safety and Insurance Appeals Tribunal (WSIAT) that awarded workers' compensation benefits to three women—Rayanne Dubkov, Linda McLean, and Carol Meagher—who were employed as communications dispatchers with the Toronto Fire Department. All three developed breast cancer and had their claims initially denied by the Workplace Safety and Insurance Board (WSIB). However, after breast cancer was added in 2014 to the list of presumed occupational diseases for firefighters under Ontario’s Workplace Safety and Insurance Act (WSIA), the claimants' files were re-evaluated.

Under section 15.1(4) of the WSIA, if a firefighter develops a listed disease, it is presumed to be work-related unless the contrary is shown. The women met the statutory definition of "firefighter" because dispatchers are included in the definition under applicable legislation, and each had served for at least ten years prior to their diagnosis, which satisfied the regulatory conditions for the presumption to apply.

The Board initially ruled that the presumption was rebutted based on the nature of the women’s employment—they were not exposed to fire suppression activities or the associated hazardous agents typically linked to cancer in frontline firefighting. This led the Board to conclude that their work was not a significant contributing factor in causing the disease.

The women appealed to the Tribunal, which reversed the Board’s decisions, holding that evidence of work-relatedness was irrelevant to rebutting the presumption. Instead, the Tribunal ruled that rebuttal could only be established by proving that the cancer had external causes, such as genetic or lifestyle factors. The Tribunal also found that the WSIB’s own policy—the Cancers in Firefighters Policy—was inconsistent with the WSIA and therefore declined to apply it in that form.

Outcome of the decision

The Divisional Court quashed the Tribunal’s decision. The Court held that the Tribunal’s interpretation of the rebuttable presumption was unreasonable and inconsistent with both the statutory language and the WSIB’s binding policy. The Court emphasized that the presumption in the WSIA could be rebutted by showing that the disease did not occur due to the nature of employment—a phrase that logically includes lack of hazardous workplace exposure. The Tribunal, however, had artificially limited the rebuttal analysis to exclude that kind of evidence.

The Court also criticized the Tribunal for refusing to follow the WSIB’s binding policy, which expressly allowed rebuttal based on whether employment was a significant contributing factor. The Tribunal had effectively rewritten the statutory test by permitting only non-employment-related causes to rebut the presumption, ignoring workplace context and exposure levels.

Given the history of the case and the clarity of the legal and factual record, the Court decided not to remit the matter back to the Tribunal. Instead, it reinstated the Board’s original decisions denying the claims, finding that any further proceedings would be unnecessary. Costs were awarded to the City of Toronto.

This decision highlights the limits of administrative discretion and reaffirms the requirement that tribunals follow binding policy and interpret statutes reasonably and in accordance with legislative intent.