It isn’t a simple equation, and he was active in promoting that culture. This seems to be less a case of victim blaming and more discomfort at speaking evil of the dead - dying as a result of your free actions does not absolve you of your own responsibility. US gun culture might have told him and his company that guns should be promoted, but the obvious lack of precaution that they showed was the main cause of death. As other people have commented, they could have fixed the gun in some way and made sure that there was no way that this could have happened. They didn’t, and this negligence directly caused a death.
Yes, he did. He was the instructor, he was responsible for deciding if she was able to control the weapon and he was the one who said, “OK, full auto”. He was also the one who accepted the job in the full knowledge of what it entailed. It just doesn’t make sense to claim that society, the parents and everyone else is to blame, but he somehow isn’t because he died. If she had died rather than him, I can’t imagine anyone rushing to defend his position and I don’t think anyone would have had a problem with blaming him for the death of a child in his care. In fact, that might have been one of those contexts where words like ‘murder’ (or at least manslaughter) could have been thrown around in a thread like this.
Actually there is often some criticism in these cases:
Also, this case is different in that a young girl was involved and could easily have been killed. I don’t think there would have been as much rage if he had killed himself or a hunting buddy where only adults were involved.