The appellant employer appealed a decision setting aside an arbitrator's award.
The arbitrator had found that while the employer breached the collective agreement regarding vacation entitlements, the respondent union was estopped from grieving the practice due to its long-standing acquiescence.
The Court of Appeal held the arbitrator's application of estoppel was reviewable on a standard of correctness and set it aside.
The Supreme Court of Canada allowed the appeal, holding that labour arbitrators are not bound to apply equitable doctrines exactly as courts do, and their application of such doctrines is reviewable on a standard of reasonableness.
The arbitrator's decision to impose an estoppel was reasonable given the labour relations context.
