That was a good point, made earlier, about the state of mind of people who do this. There is absolutely nothing you can do, quoting the laws, appealing to reason, kicking his butt, that will make him say, "Oh, you are absolutely right about riding a bike on the street. I was completely wrong. I am SO sorry. I will NEVER behave that way again." Anything you do will just provoke him further. The best rule is, in my opinion, "do not engage."