The fact that there is a camera around does not relieve a gun handler of their responsibilities to handle a gun safely.
The role of "armorer" is comparable to that of "wardrobe" or "choreographer". If a dancer kicks a baby in the face while practicing a routine, primary responsibility falls on the dancer, not the person who supplied her dance shoes nor the person who arranged the dance.
Correct. However, you will still be judged by the standards of the original ruleset, and not by how well you followed your own.
Baldwin did the firearm equivalent of cruising through a red light at 80 miles an hour without asking if anyone had actually closed the intersection. His excuse that it was a movie set does not exempt him from liability.