Clements v. Clements: Proving the Defendant Caused Your Loss
In a negligence claim, it isn't enough to show the defendant was careless. You must also show the carelessness caused your harm. Clements v. Clements, 2012 SCC 32, is the Supreme Court of Canada's leading statement on how causation is proven.
- The basic test is 'but for': would the harm have happened but for the defendant's negligence?
- It is proven on a balance of probabilities, using common sense, and doesn't require scientific certainty.
- Material contribution to risk is an exception for rare cases with several negligent defendants, where 'but for' can't be proven against any of them.
- Most Small Claims cases are decided on the ordinary 'but for' test.
The case
Mr. Clements was riding a motorcycle with his wife as a passenger. The bike was overloaded, and he was speeding to pass a car when a nail punctured the rear tire. The bike crashed and Mrs. Clements suffered a serious brain injury. The trial judge, finding expert evidence couldn't prove the crash would have been avoided without the speed and the overloading, used a 'material contribution' test. The Supreme Court held that was wrong: the 'but for' test applied, and the case was sent back.
Applying the test
- Ask what would likely have happened if the defendant had acted carefully.
- Courts can draw inferences from the evidence as a whole, including common sense.
- If there are several causes, a defendant whose negligence was one necessary cause can still be fully liable, with responsibility shared among defendants.
Photos from Pexels: A Lady Justice statue holding the scales · A law book beside the scales of justice on a wooden desk.
This article is general information for people in Ontario, not legal advice. Rules, forms and deadlines change, and every situation is different. Check the current rule or speak to a licensed legal professional before you act.
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