I agree that you are worrying too much about this. If you have no read on the player in question, then your play is correct. That is all that matters here. What you are failing to realize is that this player is playing extremely weak, and you will extract way more money out of him generally than you will lose to this specific type of situation. Sometimes, you will lose with your AJ to a weak passive player's AK, but that is just how it works. There is not much you can do about it besides playing weak passive yourself, and being scared to raise your good hands out of fear that you may be beaten. Then you will be playing like this guy, and you will become a losing player as well. Even good players lose hands.