Impaired Driving: After Cyr-Langlois - reliability, innocence & high times

While reading through legal blogs, I happened upon a post analysing the recent decision of the Supreme Court in R v Cyr-Langlois, 2018 SCC 54 [Cyr-Langlois]. The case deals with an impaired driving charge and the presumption of reliability of breathalyzer results. The blog post that I read, written by Nora Parker, reviews both the majority and dissenting reasons, and ultimately favours the dissent, asserting that the majority was too brief in its reasons and failed in addressing the larger issues that were at stake in the appeal. As I had recently written on the topic of impaired driving laws, my interest was piqued, and I proceeded to read Cyr-Langlois for myself.

Cyr-Langlois is a fascinating case. I strongly recommend reading it. While it appears simple on its face, it is deceptively complex and technical. What should have been a simple decision became a legal quagmire that even the Supreme Court was unable to navigate without a dissent. It is one of a group of Supreme Court judgements that have significant implications for the adjudication of impaired driving charges, a topic that is all the more relevant with cannabis legalization. Best and most amusingly of all, the entire case revolves around the possibility that the accused might have burped. In the post that follows, both sides of the case are examined in further detail. I then provide my own argument rejecting the position forwarded by the dissent, and by extension the concern that the majority decision calls into question larger issues of the presumptions of reliability and innocence.