Other mistake: After talking to the officers in the Höfbräu, the scene shifts to a closed business with Hogan talking to the waitress. As it shifts, the cameraman accidentally shakes the camera.
Factual error: Hogan mentions a store that offers "thirty percent off on T-shirts." T-shirts were mostly unknown in Germany during the 3rd Reich, and didn't see widespread use before the 1960s. Before that, the traditional Unterhemd, known in America as tank top or wife beater, was worn almost exclusively.
Oil for the Lamps of Hogan - S1-E14
Plot hole: The Heroes take an empty oil drum to the depot, knowing full well that Schulz will protest, allowing them to steal a full one. However, all but their barrel have snow on it. Since it's really salt, it all falls off as they load it on the cart. With real snow, that wouldn't happen. It would be quite obvious that the barrel they are taking out is not the one they brought in.
Oil for the Lamps of Hogan - S1-E14
Other mistake: Anytime Hogan steals one of Klink's cigars from the back of the humidor, he takes the hinge pin out from the left of the box (camera's right). This time, he takes out the pin, got the cigar, and put the pin back in from just what looked like just left (camera's right) of center.
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.
Reservations Are Required - S1-E15
Continuity mistake: Hogan dumps a bucket of water on Barnes and Davis each, to make it look like they were the ones who hid in the tanker. They get big wet patches on their uniforms from it, but aren't completely wet through and through - which is to be expected, after all it's just a small bucket of water each. After the next cut however, they are completely soaked like they went swimming.
Reservations Are Required - S1-E15
Character mistake: In this episode, Hogan suggests a helicopter as means for escape from Stalag 13. As a matter of fact, the allies had no helicopters operational before April 1944. The famous R-4 made its first flight only in January 1942. So unless Hogan planned to steal one of the Luftwaffe's 20 FW Drache (a maximum of ten or so existing at any given time) or a whole bunch of the single-seat Flettner Kolibri (24 total built) he was out of luck.
Anchors Aweigh, Men of Stalag 13 - S1-E16
Revealing mistake: When the "Boat" is loaded on a "trailer", you can see that it has very little ground clearance. The wheels of the "trailer" actually are hidden behind the boards like on a parade wagon. The boat has no keel and no hull below its freeboard. Besides the question of how the boat got onto the trailer if it is practically built around it, there remains the question of how it is supposed to stay afloat without a keel or a bottom.
Anchors Aweigh, Men of Stalag 13 - S1-E16
Audio problem: As the last German soldier before Hogan goes up the ramp, Le Beau is heard saying "schnell, schnell!" (fast, fast). As he says it, his mouth doesn't move.
Anchors Aweigh, Men of Stalag 13 - S1-E16
Continuity mistake: After saying that Michaels disappeared, truck and all, Klink brings his hands together, and interlaces his fingers. A second later, the fingers interlace again.
Anchors Aweigh, Men of Stalag 13 - S1-E16
Continuity mistake: In Klink's office, as Hogan tries to make a fast exit, Klink calls him back with "I'm not finished with you yet." As he does, his hands are clasped in front of him, then a second later, they are down on the desk.
Anchors Aweigh, Men of Stalag 13 - S1-E16
Character mistake: Klink claims that the North Sea is about sixty miles from Stalag 13, in reality however the town of Hammelburg and thus the nearby camp are about three-hundred miles from the North Sea.
Anchors Aweigh, Men of Stalag 13 - S1-E16
Continuity mistake: As Klink comes out to see the Officer's club, you can see Hogan is on the ground, and Kinchloe is on the boat by the shade. After a quick close up on Hogan, Hogan's suddenly on board, and Kinch has disappeared in a second.
Anchors Aweigh, Men of Stalag 13 - S1-E16
Visible crew/equipment: When in Klink's office, Hogan gives Klink the bum's rush, convincing him that he's tired. After Klink sits, the camera pans around. As it does so, you can see the shadow of the camera rig.
Anchors Aweigh, Men of Stalag 13 - S1-E16
Factual error: When Shultz is standing at the top of the ramp with a crate marked "hors d'oeuvres", talking with Carter and Lebeau, if you look to the right of Shultz's head (camera's left) you can see the Desilu Studios water tower.
Happy Birthday, Adolf - S1-E17
Character mistake: The artillery officer asks "Does headquarters expect a squad of infantry to replace experienced artillery men?" Hogan only offered "his detachment", and he's wearing a Luftwaffe uniform (and so is LeBeau). Why does the artillery officer get the idea that the "detachment" would be infantry, that is to say, ground forces (Heer) troops? To avoid confusion: Yes, the Luftwaffe did have infantry units, but those would be viewed by other branches as Luftwaffe guards primarily, not as infantry.
Happy Birthday, Adolf - S1-E17
Visible crew/equipment: When spying on a gun emplacement, LeBeau is dressed as a little old lady. When putting on his shawl before going back, you can see the studio lighting reflected on the glasses he wears.
Continuity mistake: Hogan and company use red painted gold bricks to replace the wooden stairs that they sabotaged. The steps after this episode should have been brick, but they went back to being wooden.
Suggested correction: This is technically correct; however, the series was set up to allow the episodes to be aired in any order; this is why it is always winter and some episodes do refer to other storylines and actual events/dates for episode storylines, e.g., Hogan's D-Day, which took place in June, not wintertime.
Factual error: The guard outside Klink's office and the two Gestapo soldiers guarding the gold truck have MP38/40 and a Thompson submachine gun, but carry rifle ammunition pouches instead of the long ammo pouches that carried the 30-round magazines used by the MP38/40.
Revealing mistake: When Le Beau holds up the gold painted brick and the "gold" brick, the ends reveal that they appear to be pieces of lumber. The ends seem to have grains consistent with lumber.