They used a picture of the wrong pistol. Word is the actual gun was a SAA, not the Dragoon pictured here.
Only off by 30 years or so.
This is what I was thinking. If it was a SAA then that means the actor (Baldwin) would have had to deliberately cock and fire the pistol. Which means about the only way this was an accident is if the scene called for firing the gun at the camera. Were they shooting or rehearsing a scene? If not then Baldwin has a lot of splaining to do. If this was truly an accident, and it likely was, I still feel sorry for him.