That said - I'm a bit curious about your friend's incident. Why did he have to go hands-on after making his hits? Was he not able to run away? Was he already grappling with the attacker? Or was he an off-duty LEO and was he trying to apprehend the attacker?
I ask because, as civilians, our only obligation is to survive. If we put rounds into an attacker and he lives, fine. As long as we survive, we count that as a win. We have no obligation to apprehend.
Unfortunately, handguns (of whatever caliber) will not instantly stop a determined attacker unless the CNS is disrupted - which is hard to do in a swirling dogfight, as the target areas (brain, spine) are so small. If tasers weren't so limited in range and had the ability to fire more than one shot, I'd say they were probably "better" at stopping an attack than a handgun is.
Sorry to drift off topic, but always interested to learn from actual situations.