I am a nurse too. I have worked in the ER and now I am working in a college health center. I am a brown belt in karate and my dojo teaches realistic street self defense and kickboxing style sparring (Texas Karate, Lubbock, TX, American Karate Black Belt Association); anyway....as a nurse your situation is dicey because of the overboard caution due to "what if we get sued" but you did what you did. He could have hurt someone else and probably didn't, due to your quick action. Wish me luck, red belt test Wednesday night, probably 25+ sparring matches, self defense, 11 katas and formal one step sparring.