It happens to us. Both of those things. "Was that you?" "No, I was back here." "But so was I, it must have been you." "Uh, well, I don't remember it being me..." and, as you've said, the opposite.

Same as our advice on the last entry. Let it happen and not worry about it, is what we do :P Fighting it makes our head explode. If we have severe problems with memory, we just let people it might affect, know. We've never had anybody be less than understanding. It's not like we do it *deliberately*.