TPMK type hands HU

[cardcounter0]

This is almost like the "Monty Hall Problem", you are correct, it would be +EV to switch hands with your opponent, given that you didn't hit and you know that the other hand has an Ace also.

But most of the betting takes place before this situation occurs, when you still have the advantage. You can't not bet the flop or turn thinking this river situation might occur.