Factual error: When the crew in the plane gets ready to drop the bombs on the refinery, Hogan (in the pilot seat) tells Carter (who is looking through the bomb sight) exactly when to push the button. In fact, the pilot of a WW2 bomber had no way of even knowing when exactly to release the bombs - it was the job of the bombardier, looking through his targeting optics, to know that. Carter at the bomb sight should be telling Hogan how exactly to steer to get the bombs onto the target.
Continuity mistake: Hogan Gives a Birthday Party when the prisoners capture a German plane. When it is taking off, it is an English Lancaster bomber with a twin tail. As it is flying overhead, it is an American B-17 with a single tail. Finally as it is shown flying, it is a German FW-200 maritime bomber.
Character mistake: When Major Hagel is going down the list of his knowledge of Hogan's Heroes, he mentions that their code name is Goldilocks. Throughout the series, the code was also Mama Bear, but the most used code name was Papa Bear.
Other mistake: When the General arrives at Camp 13 and is greeted by Klink, he notices Hogan and ask Klink who he is. Klink only says he's the Senior POW, the General sends his Aide to get Hogan. The Aide addresses Hogan by name, but Klink never said Hogan's name. (00:07:40)
Character mistake: As Stauffen parts company with Col. Hogan at the road checkpoint, he salutes Hogan. While that is understandable under the circumstances - after all Hogan just saved his life, it would also be highly suspicious. Both Schultz and Stauffen's adjutant were watching them, so it can't be said they did it surreptitiously either. After all, Stauffen is a German general whereas Hogan is an allied prisoner officer of inferior rank. For an officer of higher rank to initiate the salute is a demonstration of great respect and/or thanks, which, as far as anyone besides Stauffen and Hogan knew, was not warranted in this situation.
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.
Continuity mistake: Newkirk and Le Beau are getting the girl into the tunnel via the doghouse, while Hogan has Schultz distracted. Look over Schultz's left shoulder. The doghouse is in its correct position, as you can see the roof. When Schultz turns around, Le Beau and the girl are pulling the doghouse down, where it was down about one second earlier.
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.
Factual error: General Kamler awards Schultz what he calls "The Iron Cross Fourth Grade." There never was a version of the Iron cross called that. The Iron cross came in two ranks, called 2nd class ("zweiter Klasse") and 1st class ("erster Klasse"). The ranks higher than that were called the Knight's Cross ("Ritterkreuz des Eisernen Kreuzes") and were never pinned to the chest but worn around the neck.
Continuity mistake: Newkirk comes out of Klink's office with a code book, and passes it to Le Beau, who immediately holds it up and opens it. In the close up, Carter's hands bring up a book with a camera in it, and Le Beau brings the book out from his back and opens it again.