When Schultz is running with Bruno, Schultz stops to rest on the patio of the building they are running around while Bruno continues running. When Bruno comes around again Schultz joins him but quickly rests again on a bench that wasn't there before.
LeBeau is hiding under the desk while the guards search the room but when they switch shots to show the guards the desk chair is pushed in to the area LeBeau is supposed to be hiding in. Then when they switch back to the shot of LeBeau coming out of his hiding place the desk chair is moved away.
When Carter is impersonating the Luftwaffe Leutnant, the large mole on his right cheek is very visible. If the guard knew Carter, then this would give him away.
Just after turning the volume down, when Schultz rings the bell for the start of Round 2, there is a double for Kinchloe when he gets up from the stool. The hair is obviously different.
Update: The same double appears in the first round just after Carter starts his commentary and introduces himself.
Update: The same double appears in the first round just after Carter starts his commentary and introduces himself.
When talking to General Burkhalter on the phone (during the introduction), Klink bobs his head, causing the reflection of the stage lights to appear in his monocle.
Right after the introduction and mini-credits, when Carter (as a Luftwaffe Leutnant) confronts the guard at Klink's door, the stage lights reflect off his glasses.
Carter is not married, yet when he is taking off his moustache disguise, he is indeed wearing a wedding ring.
After a fighter is knocked down, the other man is supposed to go to a neutral corner for the count. Bruno goes to his own corner both times.
When LeBeau enters/leaves the office through the stove/fireplace (which has an orange glow in it, indicating it is operating and heating the room), he moves it by putting his hands on the upper trim/ridge and pushing it, without burning his hands. In Lady Chitterly's Lover: Part 1 (1970) and Lady Chitterly's Lover: Part 2 (1970), Major Hochstetter and Lord Chitterly both burn their hands when they touch the same place on the same style stove/fireplace.