The hammer would flop around and be loose to rotate on its axis. It might stay in the safety notch if placed there and holstered. If it broke in the heat o battle the liklihood would be that it would not be seated in the safety notch. My guess is the gun was fired, then made safe and lost. I suspect the spring broke while buried.
It is interesting that the bullets are protruding beyond the chamber mouths. If that were the case during battle the gun is inoperable since the cylinder won't rotate. I wonder if there was swelling of the powder or cartridges that forced the lead forward while buried.