[smittyuiop]

Looks like a fold. He's not value betting for over the pot with worse, so it would have to be a bluff, but I doubt he has air because he probably bets the flop and definitely folds the turn with air. A set or AQ raises the turn. QT probably checks behind or bets less. I don't think he necessarily has to always bet the flop with flush draw, especially with an Ace on board which could cause him to get raised. Turn call and river overbet really make sense for a flush given you probably have to be strong to bet into that board. I'd say most likely flush or maybe something like KQ turned into bluff, maybe KJ but doubt he bets that much.