Maybe it was not a ND but rather a malfunction of the firearm and that same firearm is the same used in the accident.
Possibly, we have no information either way, but I rather doubt it likely.
When something fails for a mechanical reason, it is consistent and doesn't
"fix" itself. It may only happen when the stars line up the right way, but if the cause is mechanical failure it will happen every time the stars line up the right way.
Friend of mine had a Walther, which failed so that putting the safety ON, (decocked) and FIRED THE GUN! BUT, only when the gun was held upright. He had carried the gun for 6 months, never had an issue, but my friend has short fingers and tipped the gun sideways to reach the safety. He did this every time, and the gun had no indication of problems. Another friend of his shot it at the range, and when he applied the safety, it fired. And, did it again when the gun was held upright in the usual firing position. My friend could decock it and it wouldn't go off because he tipped it sideways when he did it. Otherwise, it would fire when put "on safe".
Gunsmith was baffled, had never seen anything like that before. The parts would line up and work properly when the gun was tilted, but not when it wasn't. The point here is mechanical failure, not consistent every time the gun was operated, but consistantly failing every time the gun was operated when held a certain way. The stars lined up and it malfunctioned.
With your GP 100, pull the cylinder off and check/clean the crane, That might do it. Some years back a fellow brought me one to see if I could fix it, because the cylinder was almost impossible to turn. You could help it with your hand and get it to turn, but the leverage from the hammer & trigger alone wouldn't do it. Open the cylinder and you could hand turn it, but it would not spin. Turned out it had never been cleaned there. The cylinder axis of the crane was black and thickly coated with powder residue. Cleaned it back to bare metal and it worked fine. Good luck with yours, hope something simple like this solves the issue.
It will be interesting to read when/if we ever get the full text of the FBI testing on the gun Baldwin used. "leaks" from the report say that the FBI said it was in normal working condition. Baldwin's lawyers have claimed the gun was broken and the FBI had to fix it in order to test it at all.
Baldwin has said he didn't pull the trigger. He's reported to have said he was trying to lower the hammer and it went off. Taken at face value "something is rotten in Denmark", meaning things don't add up properly.
SOMEONE must be incorrect. I know who I'd put my bet on in this case, and it isn't the FBI, this time...