Nova Scotia (Workers’ Compensation Board) v. O’Brien

Decided: 2026-10-14. Docket: CA 548539. Citation: 2026 NSCA 73 (CanLII). Administrative law — Judicial review and appeal — Standard of review — Correctness — Appeal on question of law from Workers’ Compensation Appeals Tribunal — Whether tribunal applied a causation test contrary to law — Correctness applied to legal error — Matter remitted to tribunal for redetermination — Appeal allowed | Labour and employment — Workers’ compensation — Causation — “At least in part” language — Whether “at least in part” causation permits a trivial relationship — Requirement for more than a de minimis connection — Tribunal preferred medical-legal report over Board advisors — Error of law found — Appeal allowed | Pensions and social benefits — Workers’ compensation benefits — Statutory entitlement — Worker