Happy Birthday, Dear Hogan - S4-E26
Other mistake: Hogan returns to camp after meeting with the underground, after learning the Germans are setting a trap. Kinch went down in the tunnel to Radio London just before Hogan returned. Hogan asked the men, "Where's Kinch?" and he shouldn't send any messages. Since Kinch was in the tunnel, Hogan should have seen or heard Kinch in the tunnel using the radio. (00:07:50 - 00:10:45)
Happy Birthday, Dear Hogan - S4-E26
Continuity mistake: LeBeau meets a female underground contact in a movie theater. They have to kiss to avoid detection by the Gestapo. When LeBeau leaves the theater there are no lip stick kisses on his right cheek, but when he returns to camp he has some. (00:18:00 - 00:19:00)
Suggested correction: Simple, they kissed again before LeBeau arrived back at camp. Nothing to see here.
Happy Birthday, Dear Hogan - S4-E26
Plot hole: In the cinema, Hogan and his female underground contact avoid attention from a passing plain clothes policeman by kissing. This is wrong for three reasons. Firstly, 3rd Reich Germany wasn't so liberal that open kissing in the cinema would have passed as normal, it would probably rather have been viewed as libertine and offensive. Secondly, the scene takes place with a speech of Hitler as the background, which can hardly be viewed as romantic, and thirdly, this is even more true for the Gestapo, who was tasked with ratting out political dissent. To a Gestapo officer, ignoring the Führer's speech and kissing instead would make them stand out doubly.