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.
Who Stole My Copy of Mein Kampf? - S4-E16
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.
Oil for the Lamps of Hogan - S1-E14
Continuity mistake: Toward the end, Klink removes his monocle while talking to Hogan about the oil. Through the next few cuts between them, the monocle is off. When Hogan goes to leave, there is a shot from behind Klink, and he doesn't move, yet the next closeup of Klink shows the monocle in place.
Praise the Fuhrer and Pass the Ammunition - S2-E19
Continuity mistake: When the German officer throws the dummy grenade, it lands about 15 or so feet from Hogan. In the next shot, Hogan takes only a step or two (about three or four feet) and picks it up.
Other mistake: In the end of the episode, after LeBeau said "Hit the deck!", the camera looks to the half-track. According to the plan, there was to be a nitro charge inside it to blow it up. Watch the tarp toward the front. It twitches upward in response to a small explosion on the ground, rather than inside. The sound effects complete the illusion.
I Look Better in Basic Black - S1-E28
Revealing mistake: A very long fuse is laid down then lit by the boys to distract the guards. While it is burning, watch the fuse in the dirt - it is actually being pulled from offscreen to the right of the shot.
Factual error: In three episodes of season 1, an aircraft is shown dropping parachutists. This aircraft is a Fairchild C-119. First flown as the C-82 Packet on Sep. 10, 1944, it wasn't operational until 1947.
Happy Birthday, Dear Hogan - S4-E26
Other mistake: Hogan returns to camp after meeting with the underground, after learning the Germans are setting a trap. Kinch went down in the tunnel to Radio London just before Hogan returned. Hogan asked the men, "Where's Kinch?" and he shouldn't send any messages. Since Kinch was in the tunnel, Hogan should have seen or heard Kinch in the tunnel using the radio. (00:07:50 - 00:10:45)
Answer: It's a comedy, not a documentary.
stiiggy
Perhaps it was counterfeit. There are numerous episodes where they deal in counterfeit monies.