Welcome to British Columbia’s only weekly DUI law update newsletter. This newsletter contains the most cutting-edge information, the newest case law, and helpful practice tips for DUI defence in BC.
Authored by Kyla Lee, BC’s Impaired Driving Update is released weekly on Thursdays.
What’s inside:
- Impaired Driving Defence Tip
- ADP of the Week
- DUI Decision of the Week
- Kyla’s Insight
1. Impaired Driving Defence Tip
This week’s tip is more of a general trial tip than it is an impaired-driving-specific tip, but there’s applicability to impaired driving cases. Don’t just trust the opposing party when they say that the law says something, or a statute means something. Impaired driving cases are some of the most technically complex and rule-driven criminal charges. If you’re reading the rules in the Criminal Code or in the case law and the opposing party is telling you it says something else that does not just mean they are correct. As one judge once told me, if you look hard enough you’ll find a case that says anything. In impaired driving the law is also very fast-moving. It can vary from province to province. Appellate courts across the country can disagree. So trust your gut. The worst that can happen if you’re interpreting the law incorrectly is the judge rules against you, and had you not put up the argument in favour of your interpretation you would be in the same position. So give it your best shot when you think you have a viable argument and don’t let anyone else talk you away from it.
2. ADP of the Week
The applicant was issued a 90-day administrative driving prohibition for refusing to comply with a demand for breath samples into an approved instrument. The applicant had been in a motor vehicle collision. Police attended when he was in the rear of the ambulance being assessed. The officer formed grounds to believe he was impaired and, nine minutes later, read a breath demand. The applicant was taken to the police station where he attempted to provide samples. The applicant was unsuccessful. The applicant disputed the prohibition. Kyla Lee successfully argued that the applicant did not refuse to comply with a valid demand. Not only was the demand invalid due to the fact that the officer did not make it for nine minutes after forming his grounds, but the evidence of the refusal was weak. The officer’s claims about the status message on the instrument during the unsuccessful attempts were contradicted by the breath test ticket, which showed this was merely an interpretation by the technician. The ticket itself showed he made an attempt to blow. The adjudicator accepted that, based on the applicant’s evidence he was making a genuine effort and the weak evidence from police on the alleged refusal, the applicant had satisfied her he did not refuse to comply with a valid demand. The prohibition was revoked.
3. DUI Decision of the Week
The two-hour window for taking breath samples has been the subject of much confusion and consternation. In R v. MacIsaac, 2026 NSPC 13, the court provides a detailed analysis of the law surrounding the two-hour window, and what evidence Crown must lead to prove the blood alcohol level equalled or exceeded 80 mg% within two hours after ceasing to operate a vehicle. The court’s found that to prove a charge under s.320.14(1)(b), the Crown must establish beyond a reasonable doubt that the accused’s blood alcohol concentration (BAC) was 80 mg per 100 ml of blood or higher within this two-hour window. Because the window is a marker, the Crown must prove the time of last operation to determine when the two-hour period began. While the Crown does not need to prove the exact minute operation ceased, it must prove a defined range or interval of time beyond a reasonable doubt. The court suggested that this proven interval should not be overly broad, proposing 30 minutes as a reasonable outer limit for the range of time. Even if a driver provides a breath sample that is clearly over the legal limit, the court insists that the time of driving must still be proven beyond a reasonable doubt. This requirement exists to ensure the law is applied consistently and to uphold the presumption of innocence. Furthermore, the specific BAC level calculated from this time window directly impacts the severity of the penalty, as fines increase on a sliding scale based on how high the BAC reading was. Therefore, the court cannot simply assume a time of driving; it requires a defined interval. If police fail to obtain a breath sample within the two-hour window, the court must apply the extrapolation formula found in s.320.31(4). The court cautioned that this powerful statutory tool that avoids the need for what would otherwise be proven by expert evidence must rest on clearly proven facts regarding the time of driving, rather than mere assumptions, to avoid bootstrapping a low BAC reading into a criminal offence. To remain fair to the accused when a specific minute of driving cannot be proven, the court adopts a policy of using the end of a proven time range for its calculations. For example, if it is proven that a crash happened sometime between 8:00 and 8:30, the court will use 8:30 as the starting point for the window. By using the latest possible time, the court ensures the resulting BAC calculation is the lowest possible figure, providing the most favourable result to the defendant. This prevents the law from unfairly inflating a person’s alcohol level based on timing uncertainties. If the proven range of driving time creates a situation where the breath sample could be either inside or outside the two-hour window depending on which specific minute is chosen, the court must use the end of that interval (the latest possible time) for its calculations.
4. Kyla’s Insight
While the judge attempted to offer some protection by suggesting that the time of last driving should fall within a narrow 30-minute interval, this is still a double-edged sword. By allowing the Crown to prove a range of time rather than a specific moment, the court gives a broad target to hit. Even though the court says it will use the end of that range to favour the accused, the reality is that the 30-minute benchmark is somewhat arbitrary and based on the math of the extrapolation formula rather than strict evidentiary certainty. The notion that using the latest possible time favours the accused is also strange. It doesn’t do that if the latest time in the range puts the samples within the two hours and a post-driving consumption or bolus drinking defence with plateauing on the blood alcohol curve is made. It is unclear whether in these circumstances the court concludes this would still be fair to the accused. Thirty minutes as the benchmark for the outside limit of the range also feels weirdly arbitrary. There’s another problem with the judgment, in my view. The reliance on the electronic records from the vehicle’s automatic crash notification system call to police was relied on by the judge to infer the time of driving. Specifically, absent any evidence, the judge inferred it must have been within 30 minutes of the crash. Reliance on technology that has not been proven to work in a particular way to draw an inference like that is concerning.
5. Resources
Want to know more about impaired driving and Immediate Roadside Prohibitions in BC? Here are some helpful resources:
The BC Motor Vehicle Act: https://www.bclaws.gov.bc.ca/civix/document/id/complete/statreg/96318_00
Criminal Code Offences Relating to Conveyances: https://laws-lois.justice.gc.ca/eng/acts/c-46/page-46.html#h-121277
CanLII: https://www.canlii.org/
RoadSafetyBC: https://www2.gov.bc.ca/gov/content/transportation/driving-and-cycling/roadsafetybc
6. Contact Us
The police have their experts. You should have yours.
Charged with impaired driving? Get the lawyer who literally wrote the book on it. Call Kyla Lee at Acumen Law today. Visit our contact form or call 604-685-8889 or email kyla@vancouvercriminallaw.com
7. Featured Firm
Featured Firm: Acumen Law Corporation
Based in Vancouver, Acumen Law Corporation is one of British Columbia’s leading criminal defence firms, recognized across Canada for its work in impaired driving law. The firm’s lawyers have successfully defended thousands of Immediate Roadside Prohibitions, criminal impaired charges, and driving suspensions.
Kyla Lee, a partner at Acumen Law, is widely regarded as a national authority on DUI law. She has authored multiple legal textbooks, teaches DUI defence across North America, and regularly appears in the media explaining developments in driving law.
Acumen Law is known for its deep understanding of both the law and the science behind impaired driving cases. The team approaches every file with meticulous preparation and a commitment to protecting the rights of drivers across BC.
