> walk across the room and slap you: “if I didn’t chose to do it you cannot be angry at me.”

Of course they could. Anger is a way for the body to react without choosing as a defense mechanism against the next slap. Either your biology would recognise the anger and step back, or the other person would punch you back, making you afraid to repeat what you did.

I’m not siding with or against free will, I just don’t think your example works to prove the point.