Not in this case.
An actor isn't even responsible to know the gun safety rules.
I think we're going to have a philosophical difference of opinion about this.
I realize the legal responsibilities, of the prop master/armorer or whatever their title is, and how they are legally responsible, just as I know how the crane operator is responsible for everything on the lift and the captain is responsible for everything on his ship, whether they have personal knowledge or involvement, or not.
However, I simply cannot, and will not absolve anyone of all responsibility for what happens when a gun is in their hands.
Not knowing at least the very basic rules is not an excuse. It can be an explanation, but it's not an excuse. KNOWING the rules and willfully ignoring them or deliberately violating them is also not an excuse.
You might disagree, but to my mind, ignorance is a form of negligence, just as contempt for safety due to familiarity is also a form of negligence.
it may not be the actor's JOB to know gun safety, but I don't see that absolving anyone of their basic moral responsibility when a gun is in their hands.