Now, one thing they did get wrong was using a modern gun. Movies to the contrary, the kind of guns they had in the Old West weren't accurate enough for a quick-draw duel to be very practical. A real "gunfight" at the time would've been more like an ongoing shootout. If it comes down to speed, a gunman would probably miss on the first shot (and possibly several subsequent shots) and the knife-wielder would have plenty of time to throw the knife or to close in and stab the other guy.
I understand there were virtually no classic "fast draw" contests in the old west, it being popularized in the Penny Dreadfuls more than in reality. One of the few known actual fast draws involved Wild Bill Hickock, who later explained that the way to win was to draw fast, but then aim really carefully
before firing. While the other guy is blazing away in a panic, you take your time and hit him square.