Have you tried punching him in the face? Most people don't like that and if you do it enough they'll usually just go away forever.
But for real if you don't know details about this then you probably shouldn't try to push the point. Either get more info so you can be persuasive or wait until the dude does something fucked up again (not ideal).
But also, a lot of abusive people will just lie and wiggle out of any accountability so you might end up having to punch them in the face anyway. In my experience you usually have to be very aggressive with them at minimum or they'll brush it off and act like you're overreacting, joking, etc. I've confronted people like this several times over the years and every single time it's been a hassle, they never just accept it and move on and they definitely don't apologize
I think he's actually saying, "if you retaliate, we will escalate"