It's not a gender issue! It's a matter of teaching one's son OR daughter that verbal or physical violence is not an option when dealing with others of either sex. I never witnessed abuse between my parents during my childhood. There was moments of anger but that was usually after my Mom's discovery of my own abuse at the hands of my step-father. Corporeal punishment comes swiftly at the hands of a career Marine unfortunately.
You are on the right track by teaching your son to recognize his feelings and redirect his energy in a more positive direction. Your son's father seems to be a dark influence on him; I would not be comfortable leaving him in your ex's presence for any length of time. Supervised visits might prevent him from picking up any further bad habits. While not always possible, picking up and moving far far away from your past could be helpful.