The Supreme Court of Canada recently provided clarification in Clements v. Clements as to when the material contribution test may be used to determine causation in negligence actions. Causation may be satisfied in exceptional circumstances where the defendant’s conduct materially contributed to the risk of the plaintiff’s injuries. To meet the test, the Court must be satisfied of the following:
- the plaintiff has established that his loss would not have occurred “but for” the negligence of two or more tortfeasors, each possibly in fact responsible for the loss; and
- the plaintiff, through no fault of his own, must be unable to show which one of the tortfeasors was in fact the necessary cause of the injury, because each tortfeasor is able to point to another tortfeasor as the possible “but for” cause of the injury.
As a result of the Court’s decision in Clements v. Clements, the material contribution test will only be applicable in a very limited set of circumstances. The material contribution test is a policy driven rule and its application is necessarily rare and justified only where it is required by fairness and justice. In the majority of negligence cases, the plaintiff will only need to prove causation on the higher threshold required by the “but for” test. Under the “but for” test, the plaintiff must, of course, prove that but for the defendant’s negligent conduct, the plaintiff would not have suffered his injuries. Although it is more difficult to establish causation under the “but for” test, the Court did note that the “but for” test must be applied in a robust common sense fashion; scientific proof of causation is not required.