It depends on what he said to her. In the feminist world, there are words that are worse than assault. For instance, if she was a trannie and he didn’t support her choice to be born that way. Or if he said that Womyns Studies was a fake azz major.
I guess this is a victory for Women’s Lib and feminism. In the old days, a woman could slap a man or throw a drink in his face and chivalry prevented him from doing it back. These days, if some fat, drunk girl at a bar mouths off to him and punches him, he punches her back.