A while back a friend was showing me an old 1911 he had gotten from a relative.
He handed it to me with the magazine out. I asked was it clear and he says sure, I am safe.
Sounds like he was used to relying on a magazine disconnect of some other type of auto loader. This is one reason why I'd never disable a magazine disconnect safety feature, as so many have in searching for a better trigger pull, or on the off chance of having to fire a pistol without a magazine.
Some WW2 manufacture Browning High Powers don't have the magazine disconnect feature, the Germans deleted it to speed production. One should always make sure this feature has not be disabled when buying a used HiPower.
A magazine disconnect for the 1911 was developed and patented post WW1, but never adopted by Colt or the Army.
I can't count the number of times I've been handed an old house pistol for examination and found it loaded. Sometimes cartridges were stuck in the chamber by corrosion or solidified grease.
I've restored pistols found hidden away in tool boxes and tackle boxes, or found under car seats, still loaded and the finder having no idea how to check the chamber.
A gunsmith in a nearby city put a rusted tight 1911 in a vice , soaked it with oil and lightly tapped the slide with a mallet. Apparently there was so much lint and rust in the bore he couldn't get a rod into the muzzle or he'd have realized it had a round in the chamber.
The pistol went off and the bullet traveled through two walls and hit a man in the head around four hundred yards away killing him instantly.
I've cleaned up a .25 Colt pocket pistol that had been carried in a protective leather sheath in a coat pocket for many years. The stitching had come loose near the muzzle and over the years pocket lint and fibers from a torn lining had infiltrated till it formed a solid plug at least half the length of the bore, it was loaded of course.