The fighting words doctrine classifies a certain sort of speech that falls outside the traditional limits of the First Amendment. The idea is that the words are so personally offensive to a reasonable person that they constitute an immediate breach of the peace for no just cause, and are therefore prohibited.
However, It does NOT give anyone license to commit assault, as so many here seem to (or want to) believe.
Of course not. The assaultee could have pressed charges. If he was really stubborn it might even have gone to trial. And when it went to trial, the defendant would be acquitted.