You would think protocols were put in place to prevent that happening again. The guns used are often the real deal, so it is possible a live round was accidentally used. The actors are not really aiming the gun so I suspect he was facing a camera or designated spot for the scene. Probably fired multiple times for the scene before realizing something was wrong.
Somebody should be held accountable but I doubt it is going to be a twit who only plays the role of an intelligent person in movies.
Thanks for the comments. I agree with your take on things.
I think someone should be held accountable.