And regarding the end of tournaments (although 30 left of 130 is not exactly the end) the "normal" rules for calling and raising often go out the window and it's a case of the most aggressive player with the best grasp of who's weak wins.
Looking at the hand from the other guy's point of view..
The kind of value call he made preflop doesn't necessarily mean he's a fish, if I'd seen you make similar plays in the past I'd have certainly thought about calling (how many chips did he have as this critical).
Once he calls and you make a weak stab at it on the flop it's a fair bet you don't have an overpair (you would have checked and hoped for action) and you probably would have raised AJ a bit more preflop (people tend to raise the "weaker" premium hands more when the blinds get big as they don't really want a caller). Of course it's entirely possible you had connected with the flop but I'd have been fairly confident you either had two overcards or a low pocket pair. A reraise at this point is a good %age play, though as I say if I was going to do it I'd push and make you lay it down unless you had a J or an overpair. I'd expect to win one in three by making you fold, lose one in three to better cards and win one in three on the strength of my hand.
Of course he could also be a fish, the dividing line between great and stupid play is very fine sometimes

(see my callin with ATs at a final table the other day for a case study)