Any tool can hurt you if stored improperly. This is just a case of someone not knowing how to use the equipment, aka "A Moron."

Most probable scenario, he was fidgeting the gun around since it won't stay in place in his waist band KABLAM your dickless

1. Holster, dipshit.
2. If anyone else remembers, when the SS P320 first came out there were isolated reports of spontaneous (not negligent) discharges. It was "proven" in court that this wasn't likely. This may be worth following if you own a SS pistol.
3. Hope dude didn't shoot his dickoff.