In the scene where Hogan convinces the Count to defect, the train should be moving but the backdrop of green trees is stationary.
Hogan and Klink appear in character after the episode's conclusion to inform viewers of a programming time change. The closing credits are sped up to compensate for time.
If one looks closely, one can see the propaganda film at the top of the episode was shot at the exterior set for the TV Series Gomer Pyle USMC at Desilu studios, the same location for the Stalag 13 exterior.
A bottle of Wisk laundry detergent is superimposed over the closing credits.
LeBeau claims to have baked Hogan's birthday cake, but when it's carried to the party, it is clearly too enormous to have been baked with any of the prisoners' tools.
When LeBeau arrives at camp after his meeting with Mama Bear, he has lipstick on his cheeks which was not there when he left the theater.
This episode features an extended opening theme to include scenes of the antenna rising out of the Nazi flag which was first seen in episode 2, "Hold That Tiger."
In the opening credits, the director Edward H. Feldman's last name is misspelled Feldmam.
The opening scene begins with a graphic reading "LONDON" appearing over the London skyline.
Hogan discards a half-eaten piece of chicken on Klink's plate. When Klink later picks it up, it is entirely consumed.
The Underground's fake invasion plans are code named "Operation Anvil."
"Mein Kampf" (or "My Struggle") was the Nazi manifesto written by Adolf Hitler while in prison after his aborted Munich coup attempt.
The title refers to the method the heroes use to smuggle LeBeau into the lab.
In this episode, Klink's office uncommonly sports both drapes and curtains on the window facing the porch and yard.
Schultz requires reading glasses in this episode to determine what is written upon Carter's missing button.
When Klink's sidecar is left behind while Schultz's motorcycle speeds away, a ski-like brace, propping up the sidecar, is clearly visible.
Klink uncharacteristically wears a ring on the third finger of his left hand.
A pack of Marlboro 100's cigarettes is superimposed over some of the closing credits.
Klink has a giant glass war map in his office in this episode.
Schultz uncharacteristically fires his rifle in this episode.