You'd be surprised how much damage you can do with relatively small, sharp implements (Carotid artery etc immediately spring to mind - and while it takes up to a couple of mins, unless you happen to get immediate medical help, your basically stuffed)
Binary explosives (two parts) can be concealed as a liquid, gel (shampoo, water etc). Combine them, add an appropriate detonator - your stuffed
Shoes and lighters are courtesy of that numbskull Richard Reid (Shoebomber) - would you take chances?
Personally, I feel safer knowing there is someone onboard armed - that said, I'd feel even safer if I was armed (errrrr, maybe). Accidents happen - not knowing much about these weapons, i'm not saying nowt lol.
Was he playing with it - possible.
Did it catch on something - possible (but unlikely imo)(and without knowing holster configuration I'm pretty much guessing)
Would it have fired if trigger had not been pulled - nope
Is it useful to have any weapon "for immediate use" with an empty chamber - nope - I was taught to carry with a full mag, one up, ready to go. Mind, I was also taught good gun control etc.
Just my 0.001p worth,
Wurzel