Factual error: Baker picks up a lot of static in his radio, then suddenly signs off and says "Sounds like the radio detection unit picked up our signal." Unlike radar, radio signal homing relies entirely on measuring the signals emitted by the transmitter that is tracked. It works by comparing the strength of the signal arriving at each component of an array of directional antennae. The process is completely passive and does not cause any alteration of the signal measurable at either receiver or transmitter at all, and certainly not any audible interference or humming.
Audio problem: When the quartet plays, Klink's bow strokes don't match the music. That is all the stranger since Werner Klemperer was a proficient violinist. Maybe his playing wasn't bad enough on the stage recording?
Is There a Doctor in the House? - S3-E18
Continuity mistake: Hogan pulls a container with a red cross out of the drop box and opens it. It is labeled "penicillin" inside and contains among others several vials of clear liquid. Back in the camp, Hogan gives a box with a red cross on top to Kinchloe, saying "here's the penicillin." It is a completely different box.
Axis Annie - S3-E23
Factual error: After Carter realises Hogan got the envelope off so fast, Newkirk says "Speedy Gonzales." 'Hogan's Heroes' was supposed to take place from 1942 to the end of the war. Speedy Gonzales first appeared in "Cat Tails for Two" in 1953.
How to Win Friends and Influence Nazis - S3-E7
Visible crew/equipment: When Hogan gets up in the hotel room they're all in, the shadow of the boom mic plays on the wall he heads toward.
Continuity mistake: LeBeau and Newkirk are on a building roof and the Nazi flag is blowing in the wind with great force. In the next shot a guard tower is shown with a Nazi flag that's hanging straight down and not blowing at all. (00:01:00)
The Great Brinksmeyer Robbery - S2-E18
Continuity mistake: As Kinch answers the question about the radio, he's in quarter profile to the locker with his shirt open. After the cut to a wider scene happens, he's turned toward the camera, and his shirt is half buttoned.
Visible crew/equipment: When Le Beau signals the plane, the camera crew is reflected in the flashlight.
The Battle of Stalag 13 - S2-E5
Visible crew/equipment: As first Feldkamp, then von Kattenhorn, get in their respective staff cars, the camera crew and equipment is reflected on the doors and glass.
The 43rd, a Moving Story - S1-E23
Revealing mistake: As Carter and Newkirk sit by the wall catching their breath, a seam can be seen running vertically where two wall sections meet behind them.
The Kamikazes Are Coming - S6-E20
Revealing mistake: As the rocket blasts out of the recreation hall, the guide wires for the model are visible.
Factual error: The first episode of Hogan's Heroes (Season 1) begins with a view of Stalag 13 and a title: "Germany, 1942." That said, Colonel Hogan indicates in several episodes that he has worked in the Pentagon although construction of the Pentagon was actually completed in 1943.
The Kamikazes Are Coming - S6-E20
Other mistake: As Marya comes out of camp office, the seams between the sections of the studio flooring are visible at the bottom of the shot.
Klink for the Defense - S6-E19
Visible crew/equipment: As Newkirk and Hogan enter the office, the shadow of the boom mic plays on the wall.
That's No Lady, That's My Spy - S6-E17
Other mistake: The Kommandant's building and the barracks appear to be only twenty to twenty-five feet apart, showing that this scene of Roll Call is in the studio. Otherwise, the outdoor shots are at the studio back lot.
Revealing mistake: In the close ups, Professor Bauer's spectacles do not have lenses.
Revealing mistake: As the truck passes Carter and Newkirk, it's easy to tell they're hiding behind tarp-covered boxes rather than the greenery or rocks around them.
Other mistake: As Schultz talks to Burkhalter, it sounds like he says Captain.
Visible crew/equipment: As Schultz calls for attention, the studio lighting is reflected in his monocle.
Factual error: As the staff car comes up the street, there are a number of neon signs lit up, as well as store fronts. This is wrong as during the night in wartime Europe, such lighting would be dark to avoid night bombing.
Answer: It's a solitary cell. Steve McQueen, star of 'The Great Escape' is known as the 'Cooler King'.