Which part of 'tapping out BEFORE you've done anything are you confused about?
I believe you're talking about the sort of situation where, e.g., you start to put your hands in a position to do something, and they tap before you actually put any pressure on at all. I just think it doesn't change the question. They do have the right to ask you to let go of them before you do anything, to not put a joint lock on them at all, etc, even if you are in no way hurting them or even really doing anything. Of course there are many ways, (both verbal and non verbal), to convince them to change their mind, and some of these 'conversations' can happen quickly with body language, where you can 'ask' in a non verbal way and they can 'agree' in a non verbal way, but you both understand each other and agree so it's fine.