In defense of the Q9 call, if he blindly called against any person in this spot 100% of the time, it would probably be +ev
However, the flop play still bothers me.... instead of the board pairing on the turn, lets say its a blank like another low card instead, then what do you do with AA in my spot?
Keep the pot small if you are allowed to.
The easiest way to keep it small, strangely, might be to lead with a bet or a small raise if your oppo leads out and then check the river if its checked to you. You are controlling the pot still then. If he checks the turn and you check behind him, then he may make an uncallable bet on the river and if teh board doesn't improve all you have is still one pair.