OK, so when I was in the Marine Corps, gun safety was a HUGE THING. I mean, you get a bunch of 18-year-olds running around with rifles that are loaded with blanks during training exercises, you worry about them killing each other by mistake. You worry A LOT.

You design training procedures that strictly control the distribution of live rounds (bullets). You teach the kids that every rifle must be treated as loaded and deadly.

Then you tell them that safety is THEIR job no matter who else might be involved. If they hurt or kill somebody by firing a rifle they didn't realize was loaded, no mercy will be shown to them. They will not only be dishonorably discharged, they will spend many years behind bars ruing the fact they did not personally clear their rifle. You let them watch videos or read stories about former Marines who went to the brig and got discharged because they didn't clear their rifle.

Maybe it's that training and formation that makes me blame the person who said "cold gun" when they could have trivially known that was not true if they bothered to check.

And it makes me blame the man who squeezed the trigger, who should never have accepted the word of another person that the gun was cold. HE was firing it, so it was HIS job to clear it.