Continuity mistake: In the scene in which the POWs are distributing the tunnel dirt over the compound, Hendley is leading a group of POWs in a soldier's march. In one shot, dirt is coming out from the bags inside their trousers, but their hands are visibly swinging back and forth; they can't be pulling the strings in their pockets to release the dirt. (00:53:50)
Suggested correction: The soldiers in the center of the group have the bags in their trousers and can pull the pins. The soldiers on the edge of the formation are blocking the view of the other soldiers from the guards and can swing their arms freely.