Thats a tough one. I think I would pull my gun to try and diffuse a situation.
In a situation like that I would be more worried about the present than the future. If pulling a gun out is going to make the bad guy go away I would do that rather than let him keep the ball in his court.
Besides if you pull your gun on someone and they leave your 99% of the time going to be following that situation up with a call to the police so they can try and find the guy.
You think your going to get arrested for pulling a gun? Maybe you will but that's one of those things you just gotta deal with it if it happens. I don't think any cop in his/her right mind would try to arrest you for responsibly defending yourself.