If he had a monster, there is no reason for him to bet out after you bet the flop. At this stage of the tourney there is no way I'm giving up this hand. You are only facing a pot sized bet for all of your chips. If he would have checked, you would ended up having to put all your chips in anyways. If he has you beat good for him. My guess is more often than not you will win. Seems to me he is pushing with junk because he is afraid his hand won't hold up vs. the flush and str8 draw or he just has crap and wants the pot.