I just had a very similar situation, except I knew for 100% sure he was stealing and I had AA. It was a satellite tourney, 55$ buy in and top 15 get a $1050 entry. 17 left, I'm in 5th place, and AA vs the guy in 3rd who basically shoved every hand for the last 15
hands. So I called. he ended up having a decent hand in K-5 off, needless to say he binked me for two pair and I was out of the tourney. Moral of story, depending on the tourney bubble, it could be the right move to fold AA to a known steal