The Witness - S4-E23
Revealing mistake: As Schultz comes in the barracks door, there is a sliver of the studio background visible by the door jamb above his head.
Watch the Trains Go By - S4-E19
Visible crew/equipment: As Schultz stops the car, studio equipment is reflected in the windows.
Watch the Trains Go By - S4-E19
Visible crew/equipment: As Linkmeyer and Klink get in the car, a man in a white shirt can be seen moving around the camera position in the reflection on the car under her window.
Who Stole My Copy of Mein Kampf? - S4-E16
Continuity mistake: At the end, Colonel Sitzer pushes Hogan away, calls for music, and puts his left hand over the microphone, with his right hand hanging by his side. A second later, his right hand is mid way up the stand.
Clearance Sale at the Black Market - S4-E1
Character mistake: When Hogan addresses him, Major Kiegel sends the girls away from his table by saying "Raus!" The word "raus" used as an imperative literally means "out" in the sense of "leave the room" - he would be ordering the girls to leave the tavern, or at least the tap room in this case. It's not correct German to use it to send somebody away from a table.
Guess Who Came to Dinner? - S4-E9
Factual error: Schultz says, Von Grubner has "a castle right next to the Führer's in Berchtesgaden." Hitler's famous real estate in Obersalzberg wasn't a castle but a mountain chalet based on a former farm estate called the "Steinhaus".
Guess Who Came to Dinner? - S4-E9
Audio problem: When Hogan says "Why is it you can only trust short, dumpy spies?" the movement of his lips does not match the words.
Hogan's Trucking Service... We Deliver the Factory to You - S4-E4
Deliberate mistake: When Schultz drives off with the motorcycle leaving the sidecar behind, you can see that the sidecar has been propped up. It has to be, or it would fall over. Sidecars, bringing only one wheel to the party themselves, can't stand up on their own.
Visible crew/equipment: As the car with the kidnapped Klink takes off, the Stalag 13 buildings are reflected in the windows, along with the camera equipment and lighting. (00:01:20)
Will the Blue Baron Strike Again? - S4-E12
Continuity mistake: The cigar Hogan takes from Klink goes from green to light brown when starts to name the top invitees to the party.
Continuity mistake: As the ambulance leaves the hotel, there is snow on top of the fenders and spare tire. Back at the truck, there is snow on the fenders, but not the spare. This would be impossible as at the speed driven, the snow would have blown off any horizontal surface.
Continuity mistake: As Hogan, Carter, and Newkirk go to get out of the Army truck, the ambulance doors are wide open. As Hogan walks by, the doors are straight out toward the truck.
Clearance Sale at the Black Market - S4-E1
Revealing mistake: After Kiegel shoots out the bulb the light takes a couple of extra seconds to fade out.
Other mistake: In the tunnel where the prisoners are storing ammunition. Col Hogan tells his men the next one that lights a cigarette gets a court martial. The tunnel is lit by open flames. (00:06:00)
Continuity mistake: Col Hogan eats Col Klink's chicken leg and places it back on the plate with meat still on the bone. When Col Klink picks up the chicken leg after, there is no meat on the bone. It's stripped bare. (00:01:00 - 00:03:00)
Visible crew/equipment: As the two German officers come out of Klink's office and approach the radar truck after Kinch leaves, the shadow of the cameraman, the camera, and the camera tripod are plainly visible on the left side of the scene on the ground.
Man's Best Friend Is Not His Dog - S4-E6
Continuity mistake: The dog LeBeau is holding shifts position on his arm with each camera change.
Man's Best Friend Is Not His Dog - S4-E6
Other mistake: When seeing the tanks through the viewfinder, Carter's hands and the background are frozen, and the tanks are actually a clip of a wartime newsreel.
Factual error: When the safe doors blow, we have another case of a fuse still burning after the charge blows. Since the charge blows when the fuse is burnt up, that's literally impossible. (00:20:00)
Continuity mistake: In Klink's quarters, Hogan is complaining about Berger's activities. As he does, he goes to eat a sandwich with his left hand. After the angle change, he has both hands on it.
Answer: It's a solitary cell. Steve McQueen, star of 'The Great Escape' is known as the 'Cooler King'.