I am no commando, armchair or otherwise -- the use of that phrase appears to be an attempt to be offensive. I'm a network security engineer who shoots in a couple of local leagues, with a side business teaching concealed carry. I'm middling good among my shooting buddies, probably the bottom of the top third for members of the leagues I shoot in.

It isn't particularly challenging to make a headshot at 50 feet with a handgun under simulated stress. I've done it in competition too many times to count.

What I suspect is happening here is a divide between those who train and practice and know their own limitations, and those who do neither and have made an assumption that civilian intervention in a violent attack will usually lead to more harm being done than good. The statistics in the USA say otherwise. You're more likely to be shot accidentally by a police officer than by a civilian concealed carrier, on a per-shooting basis.