Legal? 1/2 NL Flashed hole card

[brokencarpenter]

Everyone, I've been reading for a while now but this is my first post.

I've been playing/learning for a year maybe, but definitely still a novice, and visited a B&M cardroom two days ago for the first time since I've taken the game seriously. This is what happened:

I won't comment on how the hand progressed, but I end up seeing a flop with A2o in a pot with three players.

Two aces on the flop, so I've got trips.

I check to an aggressive player who bets. Third player folds. I raise. The other guy is figuring out if he wants to go all-in.
He's directly on my left, talking right into my ear, trying to get a read. Then he turns over one of his hole cards, the case Ace. He goes all-in and I eventually fold because he's clearly got to have me out-kicked, but I was wondering about the legality of this. I folded, but my girlfriend, who also plays, says I should have alerted the dealer or the floor and could have been awarded the pot. I don't think so, but I play mostly online with the few cents I've pulled together from freerolls, so I have no idea how this should have been handled.

I played the hand poorly, I know. Just wanting opinions/rulings about the flashed card. Thanks.

Sorry if the format of this post sucks. First one. I'll get better, promise.