Corax, as I stated earlier, I think in his capacity as a producer, Baldwin may be culpable here, or may have some contributory negligence, if it is substantiated that he knew about the previous gun safety concerns expressed by members of the crew, and did nothing about them, and/or if he was aware of the accidental gun discharges previously on this set.
You express a general principle that actors should always assume a gun is loaded,
How far does this responsibility extend, in your mind?
Let's say for his first scene of the day, he does exactly what you suggest, and he finds the gun is either not loaded or loaded with blanks. If Baldwin then does his scene, and then takes a break to go to his trailer while they do another scene not involving him or this gun, and comes back a few minutes later, does he need to check the gun again?
What if he does a second scene, then has to go to the bathroom? When he returns, should he do another check? What if they break for lunch, and he comes back, does he need to check a third time?
If the answer to all of these questions is yes, prior to this incident, given that this almost never happened on a movie set before,
do you think that is a reasonable expectation of the actors?
This is not a trivial point.
This is exactly how movie sets likely run.
I am not suggesting that someone handed the gun to Baldwin in a pre-cocked position. I am asking whether it is possible, since there were accidental discharges on this set with other guns, whether it is possible for no one to have intended to fire, and for the gun to have gone off anyway due to faulty mechanics.
This seems to be something that you dismiss, saying that a gun can't fire without being cocked
or putting your finger on the trigger,
but there were accidental discharges,
so it seems like this may be possible,
and may have even happened previously. I don't actually have a case here at all. I'm just asking questions to try to learn more about the circumstances under which something like this could happen.
I must confess that I find skizzlerflake's conjectures about foul play to have prima facie plausibility. Let me put it this way. It is much more likely that that gun was purposefully sabotaged than that it accidentally discharged all by itself. The incompetence is so glaring here, that we're either dealing with the criminally stupid or just plain criminal.
I do think that you are also making a lot of assumptions here about what actors might know about gun safety, or what they "should" know.
For example, do actors even know that the guns that they are using, which are colloquially called "prop guns," are in many cases real guns,
and that the only difference between a "prop gun" and a real gun is that a prop gun is supposed to be loaded with blanks rather than live rounds?
Most often a gun firing blanks is a "real" gun. A gun loaded with blanks is still a real gun and is still really dangerous to anyone within 20 feet of it. Baldwin has a professional responsibility to know this as a person who operates guns which fire blanks. There are some guns which do not fire bullets, but only blanks, but again, blanks are still dangerous. Then there are plastic guns, and rubber guns, and metal guns that are pure contrivances or which are deactivated.
And all of this is why there is all the more reason to check.
If actors don't always know that, because they haven't been told that, then your entire argument about following standard protocols of gun safety does not hold, does it?
I would not be surprised if many actors did not know that either, unless that is something they have been trained about.