Very interesting. Most of my experience with weapons, as a Brit, is through the military. The lack of safety and solid weapon handling drills among american recreational shooters, or perceived from my point of view, has always shocked me. I suppose coming from a military background, safety is obviously the most important thing about weapon handling (an ND can earn you jail time or a serious fine in the British Army).
I'm always amazed at how brazen some american shooters are when it comes to shooting safety, especially some of these YouTube vids, etc. One big problem with the american culture of shooting just for fun is that many seem to see their weapon as a toy or sporting item rather than a deadly weapon, which is instilled in you from day one in the military.
A lack of basic skills and drills was the failure here. I'm completely amazed to read stories of people testing head-space of rounds, with their rifle pointed towards a residential area. That's the sort of thing that should earn someone a life-time ban from ever owning a firearm.