I think that you guys are over thinking a simple problem.
Get your gun out fast and shoot the guy a couple of times in the chest.
If that does not work, then shoot him a couple of times in the head. Never mind worrying about blading, indexing or any other of the trainer buzz words. They sell product. They do not win gun fights.
Tom does it just right here. Fast and violent.
Although out of character for a hired killer. If a real hired killer saw his brief case walking away, he would have shot both of the bad guys in the back, and not bothered to trap them into a gunfight.
http://www.youtube.com/watch?v=jmKR6evZRQQ