Did the gun have a transfer bar? I have two 3 screws that will not pass the infamous drop test. You load 1, skip 1, load 4, full cock, hammer down, empty chamber. A novice can count wrong or fail to cock the revolver and let the hammer down. You would still have to drop the gun or thumb the hammer (half cock would catch) to get it to fire.
It still comes down to having a live round and someone behind the camera.
Cops are not firearms experts but are known for negligent discharges.