The Battle of Stalag 13 - S2-E5
Continuity mistake: As Hogan leaves Klink to go to his barracks, there is a distinct lighting difference on the porch where Klink is. The area between the supports of the porch roof is lighter in color than to Klink's left, also the shadows of the trusses are at a different slant than the area to the right of the screen. And there are extra shadows of the light and the support to Klink's left.
How to Cook a German Goose by Radar - S1-E24
Revealing mistake: When the boys set the trash can on fire in front of Klink's office, there is a problem with the trash. While the rest of the waste paper burns down there is one piece hanging over the top edge that doesn't burn, even being in the midst of the flames on that side.
That's No Lady, That's My Spy - S6-E17
Revealing mistake: When the men are in ranks for roll call, it's snowing heavily. Given the pitch of the barracks' roofs, there shouldn't be any snow sticking. Therefore, if looked at closely, it can be seen that the "snow" on the roofs is painted in place.
Continuity mistake: When Klink and Hogan are looking at the Mustangs, Hogan has just sipped his coffee and holding the mug at chest level, at the top button of his coat. When the shot changes, he's holding it waist high. Also, the flight line full of planes is a grainy black-and-white projection super imposed in the shot of the window.
Everyone Has a Brother-in-Law - S2-E23
Continuity mistake: Hogan is reading the note from the underground on the clipboard that Newkirk brought in. When done reading, Hogan is holding the board at waist height. In the close up, it's suddenly chest height.
Heil Klink - S2-E22
Continuity mistake: The light switch for Klink's office is usually located right next to the door, with the wires going up toward the ceiling. This time, the switch is missing.
Factual error: In the very end, Klink comes up to the boys. As he stands beside Hogan, the Desilu Studios Water Tower is present behind them.
The Return of Major Bonacelli - S4-E25
Continuity mistake: When Klink is insisting on talking to the cook, Bonacelli has his hands clasped in front of his plate. When the angle changes, his hands are down on wither side of his plate.
Continuity mistake: Throughout the whole series, there are references to the building that houses Hogan and company. Sometimes it's Building 2, sometime it's Building 3. Also, there are times that Hogan's building has a direct view of the Commandant's building, and times when there is a building between them.
Continuity mistake: Newkirk holds takes Schultz's rifle so Schultz can play in the game. On Schultz's second hit, you see Newkirk clapping. In the close up, you see Newkirk's hands firmly on the butt of the rifle. Also, Newkirk is holding the rifle with the muzzle in the dirt. This would put a plug of dirt into it, but when Klink takes it away, you can see that the muzzle is clean and clear.
Other mistake: The truck was stashed behind Hogan's barracks. The Kommandant's office was on the other side of the building. While stealing the boxes of gold, there would be no way that the POWs would have been able to see any approaching figure.
Continuity mistake: Before Hogan lets Klink have the ball to hit, the camera does a close up on the volleyball. It can be seen to be a dull light brown color. After Klink hits it, and it soars up into the air the camera cuts to Hogan and Klink, and back again. When it does the ball is now a shiny orange like color.
Top Hat, White Tie and Bomb Sights - S1-E10
Continuity mistake: As Burkhalter talks to Klink, he raises his hand for emphasis on a point. When the camera cuts to a wide shot, you see his arm down by his side, much too quick without a movement to relax the arm.
Top Hat, White Tie and Bomb Sights - S1-E10
Continuity mistake: When Hogan is looking around as Klink is showing the gate to Burkhalter. Hogan's hat is up on his head in the usual position. After the camera cuts to Klink, then back to Hogan, the bill of his hat is down shading his eyes.
Will the Blue Baron Strike Again? - S4-E12
Revealing mistake: When Hogan, Newkirk, and Carter are at the Blue Baron's secret airfield, Hogan opens the barrel and stuffs in a rag and lights it so it will be a flare for the Allied bombers. The flight line and the planes on it are an obvious cutout. The fire couldn't have spread to the surrounding ground like it was shown. Also, when the bombs were going off on the airfield, you can see that the explosions are very small charges behind the cut outs.
Visible crew/equipment: Many times that there is a close up on Klink, there is a reflection of the studio lighting.
Other mistake: After Shultz herds the prisoners into the barracks, Hogan opens the door and motions to Newkirk in the tank to get going. Problem is, there are no side viewports for Newkirk to see Hogan, and it looks like he motions to the camera. Also, Shultz is at the wrong end of the building to see the tank go into the end of the barracks.
Continuity mistake: When in Hogan's quarters, they're planning to steal a Tiger Tank from the Germans. When Hogan rolls up the map, the holder it's on magically slides back into the wall. Any other time, he has to push it back.
Revealing mistake: The bunk that is the entrance to the tunnels appears to be moving upward about a split second before Newkirk taps the hidden key to activate it.
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.