The point of an armorer on set is that they ensure that the guns aren’t dangerous. The typical rules about “don’t aim at something you don’t want to destroy” doesn’t apply in a movie because otherwise all the action sequences would look dumb with people firing wildly at the ground. How stupid would it look if John Wick shoots at the floor and blood spurts out of the guys face.
That said, anyone who hires a scab armorer gets what they pay for and deserve to be prosecuted.