Alex Baldwin is one of my favorite actors. I don't care about his personality and personal views in the same way I'm an absolute fan of Tom Cruise, but can't imagine having a beer with him.
That being said, the guy killed someone! Clearly the gun worked as expected. So the issue was the way it was handled. Was it careless? For instance, if you drive too fast (carelessly) and cause an accident, you can be held criminally responsible for it. Same logic goes with guns.
- Did he personally verify that the gun was loaded and with what?
- Are blanks easy to identify, like painted blue?
Answering "no" to the questions should be considered criminal negligence. Even if someone hands him the gun and tells him its not loaded. He was an active part of that negligent process. He is responsible. He should, at the very least, stand trial. Perhaps he could be declared "not guilty" at that trial, but he should still have to go through the trial process.
On the other hand, if, for what ever reason, a live round was painted blue, than, it would remove Baldwin from the loop; attention would be diverted to who painted the live rounds. Sure, there are other security measures that can be followed:
- Modify the guns so they CAN'T shoot live ammunition
- Never aim at anyone, even with blanks.
- Properly store guns, ensure that nothing other than bullets are in the barrel (such as rocks)
- Log access to guns, who, where, when and why.
- Only practice in designated controlled areas, even with blanks.
While breaking the above rules wouldn't be criminal negligence, they could easily lead to civil claims.
Oh, one last thing: I very much doubt that Tom Cruise would make a mistake like this considering how serious he's been with gun training for his movies. One of the best fast draw on movies is him in Collateral!