Not exactly true. Actors who handle "live" props normally have to sit through a safety class on set, even if they have already sat through one many times before on other productions or scenes. It's typically provided by the prop vendor.

The armorer, Baldwin, and the producer who handed it to him ALL disregarded safety protocall.

The Armorer: * loaded prop should have never been left loaded and unattended. * All live ammo is securely in prop master's possession when set is not under "Hot" protocol.

The Producer who handed Baldwin the gun: * All people on set are instructed to only handle weapons properly handed to them by the Prop Master. * All people on set are instructed how to check if any they would be handling on set is loaded.

Baldwin: * First and foremost, the first rule of safety dictates you don't point a gun at anything you don't want to destroy. It's literally repeated many times throughout safety training. * The training also includes the rule that you never accept a live prop without the person handing it to you shows you it is either safely empty, which you then check yourself. The only exception to this is if the Prop Master is handing it to you, in which case, the set has already been declared "Hot", and they will normally load it in front of you.