Watch the Trains Go By - S4-E19
Visible crew/equipment: When Klink is by the fence acting busy and talking to Schultz, twice you can see the shadow of the camera on Klink's overcoat.
I Look Better in Basic Black - S1-E28
Revealing mistake: When Hogan, Newkirk and Lebeau are dressed as the three women captured by the Gestapo, demand the truck be stopped, the wide shot shows that the truck is already stopped, and shaken to simulate it stopping.
The Informer - S1-E1
Continuity mistake: In this episode, the doghouse that disguises an entrance to the underground is flipped up on end, and the separate floor is flipped up in the opposite direction. In all of the following episodes, the doghouse, and the floor, are one piece.
The Informer - S1-E1
Continuity mistake: In this episode, Burkhalter holds the rank of Colonel, Carter is a Lieutenant. In subsequent episodes, Burkhalter is a General, and Carter is a Sergeant.
The Antique - S5-E12
Visible crew/equipment: When Burkhalter first comes into the office, the camera rolls a little closer. As it does, you can see the shadow of the camera on Burkhalter's arm.
Continuity mistake: When Hogan and Klink are getting ready to take off, they are on a regular paved runway. In the wide shot of the plane, it's going down and taking off from a dirt runway.
Other mistake: When Carter goes to switch the full cup for the empty one, he accidentally sloshes water on Newkirk's hand and the fan of cards in it. When Carter goes to move the cups, look at Newkirk's hand. The cup exchange happens in front of the hand. The hand is out of range of the water.
Audio problem: When Hogan is taking pictures of Shultz in front of the halt-track (really, getting shots of the control panel), in the second photo, the shot is shown as if it's Hogan looking through the camera. He starts on Shultz's face, but pans down and to the right to get the control panel. Just as the view gets on the panel, you hear the shutter click, just before the camera fully settles on the panel.
Revealing mistake: When the guys are by the half-track keeping Shultz busy, if you look just above and to the left of Shultz's head, you see some tall fencing at the top of the hill in the distance. From the set up, if appears to be a baseball field outside of the studio property.
Revealing mistake: When the men are in the yard during their exercise period playing football, there is a wide shot of the yard. The half-track is to the left of the screen with Shultz next to it. If you look above the barracks, the Desilu water tower and a large metal building, possibly a studio building, can be seen.
Continuity mistake: When Shultz comes out of the NCO Club, he bumps into Klink. After yelling for a moment, Shultz talks with Klink. While talking, Klink has his monocle on. After taking a couple of steps past Shultz, he turns around and addresses Shultz again; when he does so, you see that the monocle is missing, without being taken off.
Continuity mistake: After Burkhalter relieves Shultz of command, and Klink is reinstated, Klink sits behind the desk. On the blotter is a letter opener that Burkhalter was toying with, and a black covered notebook. After sitting, Klink reaches in his jacket pocket, pulls out the same notebook, and reads from it. The shot cuts to Shultz and back, and the book Klink read from is gone, (presumably back in the pocket) and the one on the desk is gone.
Heil Klink - S2-E22
Continuity mistake: As Brauner, dressed as Shultz, gets into the staff car, he has no glasses on, as Shultz does not routinely wear them. After the shot cuts to Shultz and back to Brauner, and as the car pulls away, you see Brauner with horn rimmed glasses suddenly on.
The Battle of Stalag 13 - S2-E5
Continuity mistake: At the end, as the staff car leaves, the guard has the gate open. You see it's a single gate, suggesting the fence is a single, whereas in other episodes, you see two sets of wire. The gates are double, with a bar on the top to open both gates (inside and outside) at once.
Other mistake: Hogan is listening to Klink's office with the coffee pot, and the clear top is still on the basket that is the speaker, but you can hear Klink.
How to Cook a German Goose by Radar - S1-E24
Revealing mistake: Toward the end of the episode, a guard is watching Helga posing in a one piece bikini for Lebeau. As you look past him, you see only blue screen, no view of the surrounding property. Same when Hogan climbs up, you don't see the tops of buildings; you can tell it's on a soundstage.
Don't Forget to Write - S2-E13
Other mistake: When the recruiting officer is talking to Klink, Hogan and company listen in, as usual. The problem is the coffee pot. Any other time, they take off the top, take out the basket (which is the speaker) and plug in the power: this time, they forgot to remove the top to hear it, which would have muffled the sound. But the conversation was heard just the same.
How to Cook a German Goose by Radar - S1-E24
Revealing mistake: After Hogan and the boys decide to get rid of Tillman, they "accidentally" set fire to the trash can on the Kommandant's porch. To that end they load up a bunch of trash that's been soaked in gas. Then Hogan tosses a lit match in it. The fire starts at the bottom, but all of gas soaked stuff, and the match, were at the top.
Continuity mistake: When out at the volleyball net, Hogan is called by Kinch. While walking in, Hogan's hat is positioned as normal. When the shot is inside, the bill of his hat is down shading his eyes, and he pushes it up into its regular position.
Axis Annie - S3-E23
Continuity mistake: At dinner in the hotel, Hogan suggests a picture. Axis Annie agrees, and reaches down for the camera. After the shot cuts to a wide angle, she is reaching down again.
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.