The appellant, a municipal hydro commission, paid $921,463 to the respondent, Ontario Hydro, under a billing scheme that was later found to be unauthorized by The Power Corporation Act.
The appellant sought restitution of the moneys paid, arguing they were paid under a mutual mistake of law and that the parties were not in pari delicto.
The Supreme Court of Canada dismissed the appeal, holding that the moneys were paid under a mutual mistake of law and, absent compulsion or an illegal contract where the parties are not in pari delicto, such payments are not recoverable.
The Court maintained the traditional distinction between mistake of fact and mistake of law.
