I made the point earlier about the officer in British Columbia who was charged and convicted of obstruction for doing just that, but I find in my interviews with my clients it doesn't come up often because it doesn't occur that often.
Most people who go out and drink aren't engaging in bolus drinking behaviour. They're not slamming back 26 ounces of vodka before getting behind the wheel. Rather, people are engaging in social drinking, and those are the types of people who are getting caught under the law. It doesn't come up because it doesn't occur that often. It's very rare I would even hear of it from my clients much less have to run the defence in court.