When the briefcase is latched, the bomb is armed to detonate. After Schultz accidentally latches it, Hogan unlatches it just in time - but in the next shot, the briefcase is latched again.
When the flak opens fire, Newkirk yells 'They got the cargo plane.' However, the stock footage showed two aircraft, not one.
The story line, a briefcase bomb with the intent to kill Hitler, places the episode in July, 1944; yet, the office windows appear to be frosted over and the men are wearing winter coats.
Stauffen's aide has the adjutant's aiguillettes affixed to the wrong button - it should be one lower. Also, as a general staff officer, he should be wearing red stripes on his pants.
When Kinchloe caused the blackout in Klink's quarters, the only way he could have accomplished it with the connections and equipment he was using would have been to short out the power to the building. First, there should have been a mass of sparks when he closed the switch, as arcing would have occurred when the switch arm approached the contact as he closed it. Second, the building has two power lines going into it, and Kinchloe wired the switch to short the two power lines out. When the switch was closed, it would have blown a main breaker further up the line, causing the building to lose power, but also meaning that opening the switch would not have returned power to the building.
When Carter is outside looking for his "pet mouse", there are crickets chirping, even though it is Winter outside and there is snow on the ground.
The truck that Hogan drives to the checkpoint has its steering wheel on the right. Most German trucks of the time had their steering wheel on the left. The front license plate for the truck is WH 39495.
"Stock footage" of an American cargo plane is used when "Hercules" parachutes near Stalag 13. In select sections of the plane, it is painted "International Orange," a color which definitely would not be used by tactical aircraft during wartime.
At the checkpoint when Hogan takes the briefcase from General Stauffen to disarm it, it is obviously empty.
The drop scene shows stock footage of C119 Flying Boxcars. These aircraft did not enter service until 1948.
Hogan and Schultz catch up to General Stauffen at a checkpoint/roadblock, and Hogan says, "General Stauffen - I thought you were on your way to Berchtesgaden." The General never specified where his meeting with The Führer and the High Command would be, so, unless Hogan had information from London of this situation, he would not have known what route to take. Berlin - being the capital, it would be the obvious place where such a meeting would take place - is to the Northeast of Stalag 13, while Berchtesgaden is to the Southeast.
Sargeant Schultz tells Colonel Hogan that he lost 50 bucks gambling.
Being in Germany and since Schultz is German he should have said 50 Deutsch marks or just marks, not bucks.