Where I come from those are fighting words.
“Fighting words” is a figure of speech. Under the law, no insult justifies a violent response. Period. Of course if the words are a threat of imminent violence, that’s a different matter. Even so, the response must be proportional: if I threaten to throw a nerd ball at you, you can’t pull out a gun and shoot me. It’s the same principle: the law does not regard violence as proportional to insulting words