[dayman]

Bending your wrist and firing is possible - I don't think anyone's disputing that.
Any movement a human is capable of making is possible to counter, it's just usually they don't.

I'm not a martial arts expert by any means, but even I've had enough training to know that people never react very quickly when you surprise them. The more training you get, the quicker you can react, but most of the time you can count on a second or so - which is a lot of time in a fight.

But, if Jet Li ever has a gun on me, I'll probably just reach for the sky.