This is a very weak argument for every AD that has ever happened. Anyone with any firearm safety training, and apparently most "prop" guns are fully functional firearms, should always check to see if it is loaded or not when receiving it from another person. It should never be pointed at another person, except when necessary for a scene. The huge egos (with childlike lack of self-control) in Hollywood probably ignore these kinds of safety rules, letting some peon bear the load of responsibility instead. I accept responsibility for every one of the tens of thousands of rounds that I have fired over the years. I wonder if pro-gun actors, or at least those who take the handling of guns seriously in Hollywood, have had these kinds tragedies on set?The issue is that a prop gun and prop ammunition is not handed to an actor with the instruction that it is a deadly weapon and a dangerous tool. It is handed to them as a stage prop that is safe to point at and shoot other people with.
I just don't see any negligence on the part of a person who is operating a safe movie prop in a manner understood to be safe. Going back to the exploding sandwich example, it's like blaming the Doordash guy for delivering you a sandwich that he had no reason to believe was any different than the dozen other sandwiches he delivered in the last hour. The fault is with the person who put the bomb in the sandwich.
If someone broke into my house and rewired my light switch so that turning it on electrocutes the downstairs neighbor in his shower, am I the negligent one for flipping the switch instead of smashing open the drywall to see what it was wired to first? Of course not.
As a producer on the movie, though, Baldwin could very well catch liability for this from the position of it being "his" production, even if he is cleared of his personal liability under the accident defense. An investigation will, presumably, discover the exact chain of how this happened and open the door to various actions under the umbrella of "unsafe conditions and practices". So he could pay up for the bullet getting into the gun, even if he doesn't for pulling the trigger.