Good stuff. Then work on a world where hate speech isn't tolerated and in fact is punished and the cops aren't racist so that people feel they can have recourse to non-violent ways to resolve situations.
This whole incident is a prime example of how systemic racism works against minorities and how many people don't see it.
Subject minorities to increased levels of provocation on a daily basis and tell them that the dominant culture values the provocation more than the harm done to them and that they better not react to it. When the minorities do inevitably react (as any group would to constant provocation) the narrative is then that the minorities are more violent (and the stats show it) and don't live up to the same standards as the dominant culture. Which is then used as an excuse for further racism and persecution. Which leads to increased reactions.
Observers like yourself only see the minorities 'overreacting' and not living up to your expectations. And that argument is logical in a given single instance but completely misses the greater context. But saying 'I don't care about the greater context, just don't punch people' might be a wonderful sentiment it is a completely privileged opinion which isn't going to change the situation and in fact only perpetuates the problems.
Funnily enough what MIGHT change the situation is every racist being punched to death every time they open their stupid mouths to insult a black man. They'd probably soon learn to stop it. But I think we would both agree that's probably a sub-optimal strategy too.
You seem to have some amazing insight to the violent thug's life experiences.