As soon as he cocked the gun....that made him an active shooter. On TV, that's when the sharp shooter takes the perp out.
Fingerprints on the trigger should clarify it. Fingerprints on the cartridges should help.
SOMEONE loaded that gun...just right...cock it and pull the trigger.
Sounds like Baldwin is saying the hammer slipped when he was cocking. Under normal circumstances (sane people have an empty chamber under the hammer) that wouldn’t be a problem.
But that is STILL his fault.