The old rule "Never point a gun at anything you're not willing to destroy" seems to apply here. Camera, hand, whatever is behind the camera, etc., etc. It is stupid, and the responses are not overreactions. If you could see the firing pin hole, that would be a different matter altogether.
You're not supposed to point an unloaded gun at anyone, either.
I just tried this with an unloaded gun and my phone. The direction was only unsafe for my iPhone, which already has a horrendously cracked screen. If you go by the NRA rules, the only one he's really breaking is "Always keep the gun unloaded until ready to use."