If I'm minding my own totally lawful business and I suddenly see a random guy standing in front of me with a weapon drawn, in a solid stance, aiming at my center mass my first response will not be to go for my gun. It will be to put my hands up. Even if I'm sure he's a BG.
If I do that he might not shoot me. If I try to draw he probably will.
"Me fail English? That's un-possible!" --Ralph Wiggum
"A woman drove me to drink and I didn't even have the decency to thank her"-- W.C Fields