It’s “an accident” in the same way getting shit faced and going for a cross country drive and wrecking is “an accident”.
She violated pretty much every safety regulation, and I believe was even getting drunk and shooting the prop guns on set with live bullets. She was definitely shooting them on set, I just don’t know if they proved she was doing it while drunk.
A drunk driver doesn’t mean to kill anyone either. But most don’t say it was just an accident and try to emphasize with the irresponsible sociopath who got someone killed because they thought they knew more than the law.