Continuity mistake: After Hawkeye and Burns drive through the puddle, the mud on the colonel's face is different in the long and closeup shots. (00:02:00)
Factual error: In the hut with BJ, Zale, and The Moose, there's a Coleman 413E stove in the background. Trouble is, that this unit didn't appear until 1954, and the Armistice ending hostilities, ending the war, was signed July 27, 1953.
Continuity mistake: When Frank inspects the local workers, the laundry woman bends down to help the kid put away the sandwich Burns suspected of being a bomb. After the cut, she's upright again. (00:10:45)
Answer: The C-42 was a military variant of the Douglas DC-2. Very few C-42's were built, so it's questionable that Potter would specifically have seen that particular model, but, given his military background, it's not entirely unreasonable that he might use the military designation even when the aircraft in question is actually a civilian DC-2.
Tailkinker ★