Revealing mistake: While talking about Von Baler's daughter, Hogan is facing the building talking with Carter and Newkirk. Behind him is an open area of the camp. If you look, you can see that there is no guard in The Tower, no shadow of The Tower of the guard hut (the sun is behind them and Hogan), and the snow is piled up about three feet behind Hogan, suggesting that the background is a wall mural in the studio.
Revealing mistake: The Major goes to shoot out the light that the boys have turned on so Kinch can get the pictures. The first shot is angled too low to hit the bulb, but there is no impact on the front of the door's crosspiece; the smoke and dust comes from behind it. The second shot gets the bulb, but there is no muzzle flash, just sound. Also, there is no impact mark on the brick wall behind the bulb.
Continuity mistake: When Hogan is talking to Kiegel, Hogan's eyes are level as he looks across the table at Kiegel. After Kiegel says "Not good enough!", the camera cuts to a close up of Hogan, and he's now looking up as if the Major is standing. A moment later, the Major stands and leaves.
Revealing mistake: When the truck with Hogan and company pulls up to the Luftwaffe HQ, the camera pans to the right to look at Klink getting out of the side car. When the camera cuts back to Hogan and company, they shake as if the truck just stopped, but it can be seen that the truck was stationary.
Continuity mistake: In the beginning, the guys are listening in on Klink's office. The cup in front of Newkirk has four pencils in it. The colors from left to right are yellow, red, blue, and orange. After the camera cuts to Hogan and Kinch, the wide shot shows five pencils arranged yellow, black, blue, red, and orange.
Revealing mistake: When Schultz is on the way out after giving the guys the news about the inspections and roll calls, you can plainly see that the background behind him is a matte painting. This is easy to spot because the building in the distance is lighter in color, and there are ripples in the fabric used.
Continuity mistake: When the staff car with Leslie Smyth-Beddoes pulls in, Hogan opens the window to see who it is. As you look past Hogan, instead of a daytime backdrop, there is a black backdrop, and the wooden shutters are lit up as if it were daytime.
Continuity mistake: LeBeau meets a female underground contact in a movie theater. They have to kiss to avoid detection by the Gestapo. When LeBeau leaves the theater there are no lip stick kisses on his right cheek, but when he returns to camp he has some. (00:18:00 - 00:19:00)