Actor Jon Eric Hexum died on the CBS set of Cover Up in 1984 when he as a joke put a "prop gun" to his head pretending to commit suicide and it killed him. Brandon Lee died because a bullet was lodged in the barrel and no one checked, so when the blank exploded from the primer, it discharged a real bullet. The reason they use real guns on set is for the look and realistic feel but also for the recoil, as all they are doing is removing the bullet, the projectile. The primer and cartridge still explode with the same force as it is a REAL gun, so the actor will feel the same recoil and thus it will look realistic.
The difference in the Hexum and Lee incidents is that they are explained. In this case, there is NO explanation as to why a gun would be pointed at a director of photography and fired. She was not an extra, and there is absolutely no reason the gun should have been pointed at her. And this bullshit about "shrapnel" from a blank putting the director in critical condition in the hospital is bullshit. Was a second shot. Halyna Hutchins was a key figure in the union walk off that was planned that same day over unsafe conditions, as that gun had already fired live rounds a few days earlier. Hannah Gutierrez Reed, a 24 year old novice but daughter of Thell Reed, a famous gun and stunt expert who went all the way back to Gene Autry gun shoots, in Typical Hollywood fashion was handed this gun safety job because of her Dad at 24 years old after openly admitting she didn't know what she was doing and was incompetent. This was one of the reasons for the walkout, because an extra had fired a gun days before with live rounds(luckily at no one) but the crew was scared, and the female DP was agreeing to walk off the set with them.
This sounds like Baldwin, known to be a dick on sets, pointed the gun at her and the director and fired, probably as a joke, just like the Hexum incident, almost like saying "I wish this gun was real" because he was pissed at the director and the DP for all the complaints. BTW, there is footage of the Brandon Lee death, as he was filming a scene where he got shot in the movie. Never released.
But this cannot be an accident as there would never be any reason a gun, prop or not, would be pointed at a DP and a director unless Baldwin did it as a goof or was pissed and doing a sick joke. And right after a planned walkout by the union, who was counting on the DP, this female cinematographer, to stand behind them as the movie couldn't be shot unless she walked off as she is the only one on the set that is irreplaceable. Even the director can be replaced, but the DP has to light the shots, know lenses, bounce cards, and all aspects of photography. She walks off, no shoot. How interesting she's the one dead.