If the apparent attacker was actually defending themselves and things got out of hand, that can happen when emotions and the heat of battle are in play. Unless someone is a trained fighter, it's hard to not lose yourself in a fight especially if your defending yourself after constant attacks.
But if your the attacker and choosing to display that level of violence, well, the dude does not abide.
"I don't question our existence, I just question our modern needs" Pearl Jam - Garden
My theme song - https://youtu.be/-PXIbVNfj3s