Supreme Court of Canada Takes Another Look at the Material Contribution Test For Causation

In a recent decision, the Supreme Court of Canada (“SCC”) again addressed the use of the material contribution test.  The decision in the case Clements v. Clements, 2012 SCC 32, was released on June 29, 2012. The facts are as follows: The defendant was driving a motor bike with the plaintiff (his wife) seated behind him. They were travelling on the highway in wet weather and the bike was 100 lbs overloaded. Unbeknownst to either, a nail had punctured the rear tire. The defendant accelerated to 20 km/h over the speed limit to pass another vehicle. The nail fell out of the tire, the defendant could not control the bike, and it crashed. The plaintiff suffered a severe traumatic brain injury and sued the defendant (her husband). The only issue in dispute was whether the defendant’s negligence in driving the overloaded bike in wet weather caused the injuries.

At trial, the defendant called an expert witness who testified that the probable cause of the accident was the puncture and subsequent deflation. The trial judge rejected this conclusion and held that because of the limits of scientific reconstruction evidence, the “but for” test should be dispensed with and the “material contribution” test applied. He found the defendant liable on this basis. The BCCA overturned the decision, finding that the “material contribution” test did not apply. The decision was appealed to the SCC.

In its decision, the SCC embarked on a review of the existing Canadian and UK case law on causation. The key holding of McLachlin CJ, for a unanimous Court, was her delineation between both the characterization and appropriate uses of the two tests, which she described as “two different beasts.” The test for causation was summarized as the following two-step test:

1. As a general rule, a plaintiff cannot succeed unless she shows as a matter of fact that she would not have suffered the loss “but for” the negligent act or acts of the defendant. A trial judge is to take a robust and pragmatic approach to determining if a plaintiff has established that the defendant’s negligence caused her loss. Scientific proof of causation is not required.
2. Exceptionally, a plaintiff may succeed by showing that the defendant’s conduct materially contributed to risk of the plaintiff’s injury, where (a) the plaintiff has established that her loss would not have occurred “but for” the negligence of two or more tortfeasors, each possibly in fact responsible for the loss; and (b) the plaintiff, through no fault of her own, is unable to show that any one of the possible tortfeasors in fact was the necessary or “but for” cause of her injury, because each can point to one another as the possible “but for” cause of the injury, defeating a finding of causation on a balance of probabilities against anyone.

An extremely significant development was the SCC’s emphasis on the supremacy of the “but for” test, which (in the Court’s words) inherently requires that the defendant’s negligence be necessary to bring about the injury. The “material contribution” test on the other hand, was characterized as both exceptional and necessarily rare. The SCC clarified and redefined the test as the “material contribution to risk”, rather than the “material contribution to injury” test.

Beyond this recharacterization, the most important outcome of the decision was the significant reduction of the application and utility of the “material contribution to risk” test, which now carries three unequivocal and specific preconditions – each of which must be met in order for the “material contribution to risk” test to be applied. First, there must be at least two tortfeasors. Second, and perhaps most importantly, the plaintiff bears the evidentiary burden of proving that “[t]he plaintiff would not have been injured “but for” their negligence viewed globally.” Third, it must be impossible for the plaintiff to prove causation because the tortfeasors can escape liability by simply “pointing the finger at the other,” therefore rendering proof on a balance of probabilities impossible.

This decision has important implications for the insurance defence industry.  The material contribution test has been significantly restricted. Most significantly, this test can no longer be applied unless at least two known defendants are parties to the action, and a breach in a duty of care owed to the plaintiff can be proved against both.

Please contact your McInnes Cooper lawyer or any member of our McInnes Cooper [TBA] Team to discuss this topic or any other legal issue.

McInnes Cooper has prepared this document for information only; it is not intended to be legal advice.  You should consult McInnes Cooper about your unique circumstances before acting on this information. McInnes Cooper excludes all liability for anything contained in this document and any use you make of it.

© McInnes Cooper, 2012.  All rights reserved.  McInnes Cooper owns the copyright in this document. You may reproduce and distribute this document in its entirety as long as you do not alter the form or the content and you give McInnes Cooper credit for it.  You must obtain McInnes Cooper’s consent for any other form of reproduction or distribution. Email us at [email protected] to request our consent.