Its actually a very common problem. Gun nuts all think they are John McClane and need to keep one in the chamber at all times. They remove the magazine but never properly run the action and yeah. Its especially a problem with glocks because disassembly actually involves squeezing the trigger.

Responsible gun owners are only slightly more common than good guys with a gun.

I've met some people who really should not have guns...

Those cases are failed suicide attempts or they were otherwise doing something they know damned well was stupid.

Any given weapon is stupid easy to clear, in 3-4 seconds, and be certain it's clear. Not like bullets are hiding in there somehow.

stuff like this makes a real strong case for taking guns away from everybody