Defence. Kempf v. Nguyen
In Kempf v. Nguyen (Ont CA, 2015) the Court of Appeal stated as follows on the defence of volenti:
 Volenti, however, is not a claim for declaratory relief: it is a full defence to a finding of negligence. In Dube v. Labar, 1986 CanLII 67 (SCC),  1 S.C.R. 649, at p. 658, writing for the majority, Estey J. endorsed the following description of the volenti defence from the court’s earlier decision in Stein v. Lehnert, 1962 CanLII 85 (SCC),  S.C.R. 38:
[W]here a driver of a motor vehicle invokes the maxim volenti non fit injuria as a defence to an action for damages for injuries caused by his negligence to a passenger, the burden lies upon the defendant of proving that the plaintiff, expressly or by necessary implication, agreed to exempt the defendant from liability for any damage suffered by the plaintiff occasioned by that negligence... In Allen M. Linden and Bruce Feldthusen, Canadian Tort Law, 9th ed. (Markham, Ontario: LexisNexis Canada, 2011), the authors state, at p. 520, “[V]olenti is a question of fact normally decided by the jury”.