But who's to say a random thug on the street is going to be able to get his gun out and aimed that quickly anyway?
Tom had already started shooting the second guy in under 1 1/2 seconds, that is faster than most people can even hit their first target - and those are people who train seriously for speed. For realistic, plausible self defense scenarios I think the scene was good enough. It might not always pan out the way it did in the movie, but we can't control the way things work out every time.
Interesting discussion from everyone !