Sigh. Again he's an actor. He paid to act and gets filmed doing things that go against gun safety training (ie pointing a gun towards a camera with a person behind it and pulling the trigger.). What part of a safety course is going to cover how to do that safely?
Some actors (Tom Cruise, Keanue Reeves. etc) take their firearms training very seriously as they want to play the roles as accurately as possible. Kudos to them for this, it's no different than someone taking dancing lessons to dance better on film.
And these guys point firearms at other actors, at cameras, etc. ALL. THE. TIME.
Ultimately, the armorer exists to account for the variability of training of the actors on set. If someone is an expert marksman, great,
"I've checked your firearm and it is safe". If someone is ignorant regarding the use of firearms,
"I've checked your firearm and it is safe".
That's the (seemingly) single point of failure here.