I'd like to ask the instructors reading if they'd take the responsibility to teach techniques specifically designed to disarm a gunman. What would be their reaction if one of their students was killed trying to do that.
My personal position is : raise my hands, obey what I'm told, try to negotiate if possible, prepare to die if not (prayer, anyone ?).
I had an experience as an hostage in an armed robbery, and believe me, you don't want anybody to get nervous with brisk moves. That's why I'm quite interested with what REK (who previously presented himself as a crisis negotiator) has to say about such cases.