He and about everyone in this thread including the originator are talking shit about things they don't even slightly understand and then trying to scramble to justify.

That’s what “self-defense” is. Someone breaks the social contract and tries to harm you so you are allowed to also break the social contract and harm them.

This just isn't correct your social contract didn't magically change. You aren't excused from it by someone's actions. It is rooted in who you are not who they are. It can be described in this case by a sentence. Just because a clause doesn't apply to a particular situation doesn't mean the fuckin rule changed.

Don't cause people to come to harm by action or inaction wherein your actions are themselves justifiable to reasonable people while protecting yourself by doing the least harm possible while preserving your justifiable interests. We end up needing a lot more words to describe what reasonable is because people are stupid assholes but it is what it is.

You apply the same rule to someone trying to attack you as someone making change at the fucking grocery store. The attacker is part of the same social contract even if you end up bloodying the one person and thanking the other.