Those are excellent questions.
When you define the same term in one place and for one purpose and not for another, and then the courts interpret that, they may assume that Parliament intended it to mean two different things in two different contexts. They may be confused as to what Parliament intended, and it can create some interpretation problems. It's impossible to speculate as to what the nature of those problems is or could be, but we always try to strive for consistency in the Criminal Code. Consistent approaches lead to consistent applications of the law, so we try to adhere to a basic criminal law principle when we draft criminal legislation.
To answer your first question, I have read the record and I understand the arguments that were put forward, but it's my understanding that this person was maybe not aware of the fact that a specific decision had been taken in another context—the criminal law context that crosses over with health law principles—to not define that term, and allow the provincial and territorial law on the issue to fill that gap as requested by the medical community.