I don't think the quote is talking about "hypothesizing" anything; I read it more as "You have to update on evidence whether that evidence fits into your original model of the world or not". Instead of "hypothesizing time travel when things don't make sense", it'd be more like a stranger appears in front of you in a flash of light with futuristic-looking technology, proves that he is genetically human, and claims to be from the future. In that case it doesn't matter what your priors were for something like that happening; it already happened, and crying "Impossible!" is as illegal a move in Bayes as moving your king into check is in chess. Not that such a thing is likely to happen, of course, but if it did happen, would you sit back and claim it didn't because it "doesn't make sense"?