I think were you are misunderstanding this situation is you believe that if someone is committing a crime on/around you that you then have the right legally to commit a crime on/around them. The answer to that is that you do not. So in this particular instance 1. the initial crime of this man harassing these woman is valid (I'm sure this dudes lawyer would argue they where in a public place and the women didn't move/walk away while being "harassed" but that's a whole other story) 2. the crime of the women then physically attacking him is also valid (it doesn't matter WHY they physically attacked him, it doesn't matter how or how hard, what matters is they attacked him physically while he was not attacking them physically but only using words) 3. The crime of the women is not invalidated or justified by the crime of the man, I.E just because the man was committing a crime against the women, EVEN IF THE WOMEN THOUGHT IT WOULD STOP THE MAN COMMITTING THE CRIME AGAINST THEM, the women were in the wrong legally by committing the crime against the man.