Now if we are talking personal experience, I have never shot anyone. I did have an experience similar to yours except I didn't witness it. A Black guy I was dealing with, was attacked by another. The attacker jumped across the hood of a car, sliding toward my guy. He very quickly shot him in abdomen with a Browning .32 auto. The guy died within a few minutes.
If forced to, I will admit I like the .45 the best but the 9mm is no slouch plus it can carry a lot more rounds.
I do believe the chances of surviving a gun shot tend to go down when the size and power of the cartridge goes up. If it didn't you could safely hunt elephant or cape buffalo with a .22.
I've been accused of having some kind of penis envy for expressing that thought on this forum, but that doesn't bother me much.
I'd be a lot more bothered by some asshole who broke into my house living to visit me and my family on another day in the future to take out his revenge for wounding him.
That said, I have had no problem hunting deer around here with a .222. The range is short, and I have time to place that shot (in the neck works for me).
But under more critical and stressful circumstances, involving a sentient being like a human thug, I'll take whatever advantage I can get, and I don't see anything wrong with that.
From a practical standpoint, it makes sense to me, and not just because of the obvious physics and stress involved.
If you fired one round of buckshot, or emptied a 15 round magazine into some jackass, which makes you look more offensive rather then defensive to the authorities or a Grand Jury who very well might be involved in such a situation?