Think about he did during the 50 hands you have on him. With a VP$IP of 3.7 (not sure how this is possible unless you rounded off the number of hands) he mostly folded, this guy is a rock. I'd put him on a better ace at least, most likely a set.

It's hard to say though without actually having been there. It's just my experience especially through thousands of hours of live play that people who play this tight when entering a game will have the nuts or close to it when they make moves like this.

Is it different online? I'm not sure I just started playing at home last month.