In fairness, the actor’s job is to be concerned with how he looks and plays the part, rather than the fitness of the props. Had he been a driver of a car and the brakes failed, he wouldn’t be expected to have inspected the car prior to driving. That’s why expert staff is on hand, and in the case of real firearms being used as props, the need for that staff to be present and engaged is crucial.
The Rust situation is complex, since AB had a dual role as lead actor and also being with one of the production companies. He was also not a newbie to movie sets, nor guns on sets. He was the star of this show. So we are looking at him with a more critical eye than we might the average actor.
jmo