I'm not cross. So, you got attacked. The point isn't how you irritated someone so much that they attacked you. That's not surprising at all. It's whether you would be justified in killing that guy. Would learning techniques that culminate in stomping the head, crushing the trachea, etc, be helpful to you at all? I don't think so. In fact, I think some training on communication and interpersonal skills would be much more helpful to you, if you were receptive, so that you have the skills needed to avoid being attacked... or at least not being surprised when you are.