That is true. Actually I think Baldwin cocked the hammer and pulled the trigger.
Couple other points:
1. He did not have to fully cock the hammer and have it lock back for the gun to fire. If he pulled the hammer just a little, or even quite a bit but not far enough for it to lock, and then released it, it could have fired. He is still the one that fired it.
2. He states he took someone else's word that the gun was safe to use. He states that that procedure has worked up until now. Well anyone with a safety background will tell you that doing something that is unsafe but it never had a bad outcome does not mean it is safe. You are the one that will be handling the gun. Why would you just accept someone else's opinion that the weapon is safe? Clooney is right. He checks the weapon and shows it to others around. Baldwin discharged the gun and killed that woman. No one else did it. Be an adult and own up to it. You shot her. Period.
3. Initially, like in the first day of the news about this, there were reports that crew were using those guns to target shoot during down times. Right off the set. So don't tell me that you do not know where the live round came from and that there was not supposed to be live rounds on the set.