I've got a real simple answer to this. I'm not going to give away "the surprise" by hinting that I'm armed. I will do everything I can to evacuate and de-escalate, but when it comes down to it, I care about mine and me, I don't care about his and him. There will be a brief pause between the time the gun comes out and the time it fires. During that brief pause, I will be reading his eyes. His eyes had better do a whole lot of talking, and they better be saying, "Oh crap, how fast can I get away?"
If I draw, it will be to shoot, and it will be a surprise to everyone around me.
*Opinion worth what you paid.