Judges, we know, have long memories. They talk amongst themselves. It doesn’t do a lawyer’s clients any good, let alone the lawyer’s reputation, if judges begin with the assumption counsel doesn’t know the applicable law.
For the second time in the past two months, I’ve heard litigators who should know better tell a trial judge that, in a negligence action, all a plaintiff has to do to establish factual causation (cause-in-fact) is to prove, on the balance of probabilities, that there “was a substantial connection beyond de minimus between the negligence and the injury”. This time, unlike the last time when, at least, counsel referred to a 2011 BCCA decision as the basis for that statement, counsel asserted, orally and in written submissions, that Clements is the authority for that proposition. There was never, in either the oral or written submissions, any mention of any of the paragraphs, sentences, phrases, words, statements, etc. in Clements all of which make it clear that the requirement is “necessity”. I’ll quote only paragraph 8:
 The test for showing causation is the “but for” test. The plaintiff must show on a balance of probabilities that “but for” the defendant’s negligent act, the injury would not have occurred. Inherent in the phrase “but for” is the requirement that the defendant’s negligence was necessary to bring about the injury ― in other words that the injury would not have occurred without the defendant’s negligence. This is a factual inquiry. If the plaintiff does not establish this on a balance of probabilities, having regard to all the evidence, her action against the defendant fails.
It’s also worth mentioning that no version of the “substantial connection more than de minimus” mantra, literally or in paraphrase, appears in Clements; nor does the phrase “de minimus“. Also, the only time “substantial connection” is used in Clements is in paras. 20 and 21: the first time in a quotation from Snell and the second time in explaining what the usage meant. I’m not going to quote those portions of Clements. This link will take you to them.
In the most recent instance, the written submissions (maybe lifted from prior submissions?) also asserted that all a plaintiff has to do to establish factual causation is to prove, on the balance of probabilities, that the negligence “caused or materially contributed to” the injury. Given that the citation for that was Athey, it’s open to wonder what counsel meant by that statement. If counsel meant only the explanation that the SCC gave, in Clements, for the later use, in Athey, of “material contribution” in a sense that wasn’t a reference to the Athey material contribution test –
 This Court, per Major J., discussed the limitations of the “but for” test and the propriety of exceptionally using a material contribution test. Major J. emphasized that a robust common sense approach to the “but for” test permits an inference of “but for” causation from evidence that the defendant’s conduct was a significant factor in the injury, and concluded that “[t]he plaintiff must prove causation by meeting the ‘but for’ or material contribution test” (para. 41). Major J. concluded that the 25 percent contribution found by the trial judge was a “material contribution” sufficient to meet the “but for” test. The term “material contribution”, read in context, does not detract from the fact that the Court in the end applied a robust, common sense application of the “but for” test, in accordance with Snell.
counsel didn’t make that clear.
The “material contribution to risk test” as explained in Clements as what the Athey material contribution test is to now be understood to mean wasn’t argued.