I know a whole lot about Firearms, and Zero about the idiosyncrasies of the movie business, so I’ll take your word for it.
The information about the shooting scene and the shooting
itself was derived from the media reports.
As an amateur photographer, I know what a side on shooting
would look like, hand extended but not aiming the gun at the
other person in the scene.
An industry agreement on how guns would be used in movies
to eliminate any risk to people on set, should be doable.
I never consider a gun unloaded. The practice of aiming
a weapon at another human is foreign to me, movies or not.
There is also the ability to create a gun that looks just
like the gun they want to use, but it would not have a
place to load ammunition.
The gun could be used as they wish, and the sound and other
affects added in post production. They can do anything with
CGI these days.