According to FBI Statistics, in any given year, +/- 22% of all peace officers killed, will be killed with their own sidearm. Sometimes more; sometimes less. But it averages at 22%.
Criminals practice assiduously on each other on how to disarm a peace officer and kill him or her with their own gun. There are video tapes of convicts in prison, practicing to do it.
Years ago, when I was going through the Academy of a very large peace officer organization, when we were working on "gun retention tactics," one of the instructors told our class, "Hey, why should a criminal carry a gun?? You're carrying one for him." I never forgot that.
As a non-p.o., you are not required to take an attacker into custody. If at all possible, do not allow yourself to get into a criminal's "kill zone." Many of them know exactly how to take that pistol away from you.
I can't speak for anyone else, but if I lived in a State in which it was a no-no to shoot an unarmed attacker, I would protect myself if I surmised the attacker meant me great bodily harm or the threat of death. I'd rather deal with a jury, than have my wife deal with the Coroner.
JMHO.
L.W.