Baldwin was the Producer so is on the hook as the person who has ultimate “The buck stops here” responsibility for what went on in this movie production. There is no way he can escape that.
The actor/actress” are not gun experts and are not expected to be one as far as checking the weapon themselves. The person who hands the gun to the actor is supposed to be the “expert” and have done all necessity and required safety checks. That individual is on the hook criminally and for any civil actions.
I didn’t know that Baldwin was the producer. If so, yes he’s going to be “ on the hook “ as you say, (or at least his production company) especially since his production manager was told about earlier gun discharges and apparently did nothing.