Horrible play? MTT donk looking for advice

[MikeR]

3rd level of a $24+$2 touney in Fulltilt with about 900 players. I've got everyone but one guy covered and get AA utg. Raise 3xBB, everyone folds to BB, who has slightly less than average stack and he calls.

Flop is 555. This is what I'm thinking. Chances are he doesn't have a 5, and if I push all in he might think I'm trying to make a move with AK or AQ and maybe he'll call with whatever pocket pair he has, giving me all his chips, or folding, giving me the blinds and the money in the pot.

He turns over Ten Five offsuit, and takes most of my chips. Was this a bad play on my part, as far as my thought process? I'm thinking my preflop utg raise says nothing about a hand that matches up with 555, and there's a great chance he calls KK all the way down to 22.

I suck at MTTs besides luckboxing a couple of wins, and would love any advice.