Therefore, any blanks in the pistol would be discharged, and need to be replaced with more blanks. If they just had dummy rounds in the pistol, it wouldn’t matter. But dummies don’t flash or go bang.
They weren’t shooting a scene so there would be no need for blanks in the gun. As far as an actor or actresses not knowing the condition of each firearm they pick up, they could know not to point it at someone and ask “where are the ballistic shields?”.