@dropdead,
To answer the question, it was not wrong for you to stop him. In fact, in my opinion you should have just left after the first disagreement. Once things broke down you had no obligation to help him finish.
You should think twice before putting yourself in this situation again. Having sex while you are drunk rarely ends well for either person. And, doing anything sexual out of a sense of guilt is never good (you don't owe a partner anything). If you are having sex with people you don't know well after drinking, you should figure out how to change your behavior. I would give this same advice to the man (I believe in equality).
My advice is to find partners that you have a relationship with, that you can respect and trust that they will treat you with respect. If someone doesn't do this, you should get up and leave right away with no sense of guilt. Great sex is when both partners are listening to each other and trying to please each other.