I seem to recall fairly extensive discussions about whether or not you can tell a misclick or not. Maybe here:
I’ve not read back over all this but the point is that the position of the intended move (if known, as uberdude points out) doesn’t really say anything about whether an undo was for misclick reasons or not.
So I would suggest you either accept requests and assume good faith or refuse them as is your right and don’t worry too much about your opponent’s intentions.