I think it's tragic, and I would have a hard time believing that anyone would do something like that on purpose for any reason. I'm a little surprised that anyone would allow a functional firearm on a set like that, to be honest. There have been too many incidents of people injured or killed by blanks and other mishaps. Any time you have people handling lethal weapons who aren't adequately trained for it you have a very dangerous situation. I know not everyone had things like "Treat every gun like it's loaded, all the time, even toy guns" and "Don't ever point any gun at anything you don't intend to shoot" drilled into their heads since early childhood. You really do have to be careful to the point of paranoia. I know that in the movie industry it's sometimes necessary to have guns aimed at people during filming, but I can't imagine a way to make that safe enough with actual guns that I'd be comfortable with it -- even with trained people, and most of the actors are most definitely not.