It is a Wild West action movie....really boring if the actors always point their guns in a safe direction and don’t pull the trigger! ;-)
The armourer (Gutierrez) should have gotten a few years (perhaps 3) and Baldwin since he was apparently messing around between takes should probably get the 18 months. The “bottom line/buck stops here” responsibility was with the armourer to make sure all guns on the set/area were loaded with blanks with no live ammo around. i.e. she has possession of all the guns on set and hands them to the actors right before the scene is “filmed”/recorded after triple-checking them for blanks. Then takes back possession of the guns after the scene is done.
You miss the point entirely. Baldwin was not “filming” when the incident took place. It was, as you say, in between takes, and Baldwin was goofing around with a gun.