When Kirby lights the lantern, there's an obvious, flickering flame and the lantern glass is clear. But when Saunders uses the lantern while crawling in the tunnel, the glass is opaque and the light is very bright, as if there is a bulb in the lantern. When he crawls out of the tunnel, the glass is clear again and the flickering flame is seen.
When Saunders has a blade at Barton's back, his hand keeps changing from an underhand hold to an overhand hold.
The men realize that the dirt from the tunnel that was previously dug had been hidden in the ceiling. There is a shot of Doc keeping a lookout at a window. When Saunders tells the men to move the stove, Doc is suddenly already there at the stove with the others.
Capt Reardon's helmet has the proper two bars for Captain rank on front, and only a single bar (Lt.) on back.
After Kirby lights the lantern, he shakes the match but doesn't make sure it is out before dropping it on the hay covered floor.
When the prisoners escape and the alarm sounds, two Germans on regular patrol appear to say something, then they just continue walking. They don't even take their weapons off their shoulders in case they come across the prisoners.