At one point in the epsiode, a road sign is placed to divert the enemy -- the sign displays English words, although the scene takes place in the middle of Germany.
No bulletin board appears behind Klink's desk in this episode.
In an oddity, Carter has to escape a collapsing tunnel and comes up through a foot locker.
Larry Hovis is wearing a wedding ring. In other episodes, his character, Carter is protrayed as single and naive in the ways of women. (Larry Hovis refused to remove his wedding band during filming, and thus, Carter is usually shown wearing gloves.)
There is a bulletin board in Klink's office.
Klink's living quarters are shown - furniture and set design of his living/dining room and kitchen, none of which are used again.
William Christopher, who played Lt. Donner, is most famous for the role of Father Mulcahy in M*A*S*H.
The soldier guarding the truck with the heavy water is carrying an American Thompson submachine gun.
In one scene, they convince Klink his office is on fire so we see him gather up his papers and go over to the window to jump - except the location of the window does not match the exterior of his office building setup.
The prisoners sing the Beer Barrel Polka to mask conversations from Klink's hidden microphones.
The prisoners have a bright red coffee pot and colored mugs in this episode. Later, these were removed in favor of more bland tin items.
Jon Cedar, who usually played Corporal Langenscheidt, is listed as 'Guard' in the closing credits. He is the guard who opened the gate for Schultz and Newkirk.
As in the 7th episode that aired (German Bridge Is Falling Down), Carter is seen wearing a wedding ring.
Hogan impersonates General von Himmelberger of the German General's Staff.
Throughout the episode, the DuBois character is called Henry, but in the closing credits his first name is Emil.
Carter is asked to tutor LeBeau in rudimentary chemistry, yet allows that, while running a pre-war pharmacy in Muncie, Indiana, he knows very little about chemistry.
Hogan appears in a Luftwaffe uniform and impersonates Major Hoople.
Early in this episode, Hogan reveals that Kinchloe's rank is Staff Sergeant.
Hogan (and the main co-stars) live in Barracks 2. For some odd reason, the sign reads Barracks 3. To compound it, in one scene, when the door is open, you can clearly see the barracks in the background says Barracks 2 - only problem is that there is no barracks between Hogan's barracks and Klink's office.
Klink, Kinchloe & Newkirk are all seen smoking cigarettes.