i think the third option is closest, but that it's a compound problem.
1) the decision was no doubt made in consultation with his advisers, which were trying to tap into a current of critical theory that sees quebec as a colonized population. this is absurd all the way through (quebec is a colonial state, not a colonized one), but it is an iteration of a type of thinking that is currently a kind of a fad amongst young people and would lead many to the conclusion that "reverse discrimination" is impossible. they really wouldn't acknowledge english minority rights as possible because of the system of systemic discrimination designed to oppress francophones. it is simply historical ignorance to try and look at francophone canadians the same way you'd look at african americans, or indigenous canadians, but what they're doing is blindly applying the theory over top of their ignorance of history for the reason that it is fashionable. this is exactly how his advisers think, and it is no doubt at the the actual root of the fiasco.
2) he didn't react. he should have realized that the particular question in front of him was an exception to the strategy. now, do you blame his advisers for not being rigorous, or do you blame him for being slow on his feet?
believe it or not, i am not a liberal partisan. i just don't usually find much of substance in the media criticisms. i don't think the media is understanding where this whole fiasco came from, and if it did it would likely be that much more appalled. but, part of it is actually a generation gap built on top of an education gap. believe it or not, most youngish, educated liberals would actually agree with the principle, even if they acknowledge the need for an exception in this scenario.
i'm reacting negatively to the entire premise, because it's a false equivalency built on top of a logical fallacy. but, i'm an anarchist; i don't like foucault. so, this is some ideological leftist infighting.....
http://www.cbc.ca/news/canada/montreal/trudeau-language-fallout-1.3941934