Sure, guns go off all the time, heck, my gun safe is full of holes from my guns going off. Very little information in the news report but if I was LEO I'd be leary of the gun just going off, I'd check for a bullet hole through clothing, if none found, I'd ask the man if he was handling the firearm.
Another one of those guns that just do off. :roll eyes:
With what would he be charged?