Glocks - don't just... "go off."
If you guys are all done with your Kool-Aid,
any pistol can fire when dropped. All it takes is an irregularity or chunk on the breech face, protruding/stuck/broken striker/firing pin, proud primer, and whatever else I can't remember, but Murphy surely will. None of that is necessarily the gun's fault - life happens.
That said, I also figure the guy dropped the pistol and caught the trigger. Plaxico Burress redux.