The attached video shows a real life defensive encounter. In it, the intended victim doesn't pull his weapon immediately. He waits for an opportune moment. In the scuffle that ensues, he isn't concerned about whether he is using an isosceles stance or a weaver stance nor a surprise break in the trigger pull, and he may not even be using his sights. And after the threat hits the floor, he still finds cover, asseses the situation, and fires more shots as necessary.
In other words, the winner of an actual gunfight isn't always going to be the one who can draw and shoot the fastest or even the most accurately. It will most likely be the one who thinks and reacts the best.
https://www.youtube.com/watch?v=jv-ZSt2AMqk