Upon the arrival of General Burkhalter, Klink asks after his wife and Burkhalter is standing with arms at his sides. When Burkhalter replies (in the next shot), his arms are folded.
Right at the beginning of the introduction, Newkirk walks out of Klink's office and passes the code book off to LeBeau. LeBeau brings the book up and holds it in front of his chest. Cut to a close-up of LeBeau's chest, and he brings the code book up in front of his chest again.
At the end, after Hogan pulls out the fuse, the wires attached to the fuse are arranged differently in the wide shots vs. the close-ups. The close-ups show the white wire standing quite high off the fuse, while the wide shots show it hanging limply, only standing slightly above the end of the fuse.
Unless Hogan brought one from home, the wire cutter used in the bomb defusing was a "Crestoloy" brand of the "Crescent Tool Co." made in the USA and would be very rare at best in the area of the camp that is dominated by very efficient organic tool makers.
As Carter is finishing up developing the pictures of the code book, Hogan indicates they are bombing the railroad outside of camp. There is no way the allies would have been bombing a railroad outside of a prison camp, as the bombs of the day were not accurate enough to guarantee that the prison camp would not be hit.
The camera Carter uses to take the pictures of the code book the second time is a 35-mm Single Lens Reflex (SLR) camera. The negatives that Carter brings out appear to be 16-mm (if not slightly smaller).
Kinchloe tells Hogan that Carter is sending the code to England. First, Carter is not the radioman; if the code is sent by radio, then Kinch should be the one sending it. Second, sending the entire code by radio would take hours; it would be better to send the pictures that were taken back to England. Third, the stolen code is too valuable to send by radio; if the message was intercepted, the Germans would know that their code has been stolen.
When defusing the bomb, Hogan is just in a summer service shirt and sweating, while Klink and Schultz are in their winter coats.
In some of the scenes in the compound where Hogan is defusing the bomb, there are electrical poles and lines in the background. These are the power lines to the residential neighborhood on the other side of the berm in the background.
In the introduction, just after General Burkhalter arrives, the Gestapo officer gets out with the radio detector. It is a rectangular box with a flat lid and a latch to hold the lid closed. There are handles on each end of the box so it can be carried. After the mini-credits and the issue with the film, the view changes to Klink's office. As Klink is putting the code book in the safe, the radio detector is on the chair next to the Gestapo officer. The lid has been removed, and the pointer is visible. Note that everything is recessed inside the box, and the pointer is level with the top of the box. The handle is also visible by the Gestapo officer's arm, and the box is quite square and flat on the bottom (as it has been all along). As Burkhalter walks around the corner of Klink's desk, the box is still visible sitting on the chair. Finally, the Gestapo officer picks up the detector to put it on Klink's desk - only now there are no handles on the ends, or latches to hold the top in place, the pointer and all the controls are visible above the top of the box, and the bottom of the detector has molding at each end to act as feet. The handles on the ends have been replaced by small wooden knobs (like those on kitchen or dresser drawers) to carry it. It is apparent that the original incarnation of the detector required the camera angle to be above the box to see the pointer and controls, which would have required considerable changing of the camera angle, particularly when the detector is carried around to find the source of any transmissions. Once the issue was recognized, they did not re-shoot any of the initial footage.
The first time the arrow on the radio detector points, Klink says its the front gate. Third time it points to the same direction as the first time and Klink says its Hogan's barracks.
In many of the scenes, there are unusual shadows on the wall behind the object indicating where the production lights are placed. In the outer office, the cabinet is casting a shadow on the wall, indicating that the lights are to the upper left of the camera. Men are casting a shadow on the wall behind them in Klink's office, indicating that the lights are to the upper right of the camera. Even in an outside shot, there are shadows behind the men.
The radio detector that Gen. Burkhalter brought with him would have homed in on the flagpole atop the office building, since that was the antenna used by Hogan and the boys, and the radio signal would have been strongest there. There would have been virtually nothing detectable in the direction of the barracks, since all of their equipment was underground.
According to Kinchloe, Carter is right under the real bomb that landed in the camp, trapped by a tunnel collapse (which is not detectable from above). The bomb would not have embedded itself in the way it did - it would have caused a large cave-in where it landed, and the whole tunnel system would have been revealed.
When Carter is taking the pictures of Klink and the code book, LeBeau has his fingers over the lower part of the code on 2 of the photographs.
Just after the introduction and mini-credits, Carter comes out of the dark room and opens the camera, whereupon he discovers there is no film in the camera. It makes no sense that he would open the camera in the lighted tunnel rather than in the dark room - even though, theoretically, the film cartridge would have been safe to take out in the lighted tunnel. In reality, he would have been in the dark room, already developing the film (if there had been any film in the camera).
While defusing the bomb, neither Klink nor Schultz would have been anywhere near it. Klink, the coward he is, would have been hiding in Klink's office. Klink would have ordered prisoners to defuse the bomb, with Schultz guarding them.
After General Burkhalter arrives, he, Klink, and the Gestapo officer (with the box) go into Klink's office. Hogan never sets up the bug receiver in his office to listen in to the meeting in Klink's office. He would never have been distracted by the code book/film situation enough to have forgotten to listen in on the meeting (or just ignored it).