Alex Baldwin as an actor pointing the gun and pulling the trigger was not what he did wrong. All of the was planned and part of the scene. Movie sets have different and strict rules about guns. You get the weapon from the armorer and only use it for the actions in the scene.

So if the scene doesn't have you removing the magazine you don't remove it. Even to check if it's loaded. This prevents stuff like the actor goofing around and accidentally loading it.

What Alex Baldwin the producer did wrong was ignore multiple warnings and walkouts about the armorer not taking proper safety precautions. Like taking the guns off set to go shooting. He could and should have fired her.

Alex Baldwin would have been just as guilty if it was some other actor who had aimed and fired the weapon.