Is it possible he had AcQs or similar to give him the ace to draw on the turn and TPTK? I think he might have thought you had a smaller Q there and put you to the screws. I usually don't find myself working about flushes for rocks like that too often, and often I can tell when they do have it from AKs or something like that. I think it was a good move, although I'm surprised he didn't call there, given how much money was already in there. I thought there was around $175 in the pot at the turn, so I can't see how he can make that hard bet there and not at least be prepared to consider calling for the rest of his chips. He must have had shit and had you on an ability to get off an over pair given the end.

Nice hand