I don't know what made me think of this, and I'm sure there are lots of variations, but I'll try to just keep it on the main theme.
You are someplace and someone you recognize as being famous (ie. movie star) decides that you are sitting at their favorite table at the restaurant you are in and decides to start a rant with you. (ie. you are not the bonehead that starts the whole incident).
As you get up from your seat, you are verbally responding to the rant/defending your position. Suddenly a BIG guy is coming at you with apparently no intention of stopping. You quickly decide it is probably the bodyguard, and that his impact is going to hurt.
What level of response is appropriate/justified?
Would drawing on him only justify his shooting you in the performance of his duties?
Do you have to submit to physical force, believing the situation is what it is, a bodyguard performing his duties? (ie. being knocked down, or physically removed from the restaurant)
Other pertinent points:
This is not an official ie. secret service, rather a private bodyguard.
This is not a chance to show the famous person that you have every right to be there (even if you do). You are willing to retreat, but it looks as if it will get physical before you can.
Disclaimer: This is my first scenario to dream up, and I'm sure I have left out some key points. Just work with me, please.
Anyone who works in the industry of private security, please weigh in.