Bison Transport employed John McCarthy as a long haul truck driver, a job involving substantial safety responsibilities. The company maintained a drug and alcohol policy governing its drivers. Following a second positive random cannabis test, it dismissed McCarthy for cause. He sued, arguing that the dismissal was wrongful and that the company owed him overtime pay.
In McCarthy v. Bison Transport Inc., 2026 ONSC 3729, the Ontario Superior Court of Justice examined the content of the policy, how it was communicated and enforced, and the evidence about the driver's conduct. The employer's success wasn't based simply on putting the words zero tolerance into a policy. The court considered whether the rule was reasonable in a safety sensitive transportation operation, whether the employee knew about it and whether the discipline was supported by the actual record.
McCarthy also raised disability related arguments. Workplace addiction and dependency can engage human rights accommodation duties, but the evidence in this proceeding didn't establish an actual or perceived drug dependency disability that required the employer to accommodate him. The court rejected his wrongful dismissal claim on the particular facts.
The overtime allegation failed too. The court found that some of the amounts claimed were outside the applicable two year limitation period and that the remaining alleged overtime wasn't supported by sufficiently reliable proof. The action was dismissed in its entirety.
For employers with safety sensitive work, the case reinforces the importance of more than a signed acknowledgement. Rules have to reflect the work, be understandable and be applied consistently. Records of testing, discipline and workplace expectations matter when an employer later relies on a policy to justify termination. And a human rights analysis still has to be conducted where evidence of disability or perceived disability exists.
For employees, the decision shows that evidence is central on both sides of the case. A claim of accommodation must be grounded in the circumstances, while a claim for unpaid overtime needs dependable records and attention to limitation periods. This judgment shouldn't be treated as permission to dismiss every worker who tests positive for cannabis.
Source: Ontario Superior Court of Justice, McCarthy v. Bison Transport Inc., 2026 ONSC 3729, full judgment available at https://www.minicounsel.ca/scj/2026/3729