Except that ignorance of one's own state of intoxication is NOT a defense against drunk driving.
It doesn't matter if this guy knew his drink was spiked (if it was). The fact is that he was driving while intoxicated, which is against the law.
non, mon ami. In Canada, a serious offence, like DUI, cannot be an absolute liability offence.
Most ticket-offences, like speeding,
are absolute liability, so it's no good trying to prove that you didn't mean to speed, or that you had a good reason to speed. The fact of the speeding is enough for a speeding conviction.
But in serious offences, like DUI, the prosecution has to prove guilty intent, and now you
are allowed to "put your side of the story". If the court believes you weren't at fault, for some reason, as appears to be the case here, you can be acquitted.
But don't count on being able to do that -- note that it makes the news when it happens.