Goofs

One of the East Germans opens a bottle of Coke by smashing its neck (in classic Russian-brute style.) But when the carton is returned at the gate, all the bottles were quite intact.

The diameter of the monocle is notably reduced after its transfer from the Count to Otto.

When Otto rides his motorcycle back to East Berlin, there is a balloon on the tailpipe with "Russki Go Home" printed on it. As he rides through the streets of West Berlin, the lettering is on the side of the balloon. By the time he crosses into East Berlin, the lettering has shifted and is now on the rear.

Schlemmer calls his former superior officer in the SS "Herr Oberleutnant". The SS had no rank of Oberleutnant nor did its members call each other Herr. Oberleutnant was a German Army rank. The corresponding SS rank was Obersturmführer. In the German (dubbed) version, Schlemmer correctly addresses him as "Obersturmführer".

The sign that would have been displayed as you left West Berlin into the Eastern side via the Brandenburg Gate, would have read 'You Are Now Leaving The British Sector' as that area had been in The British Zone of occupation since 1945. Hence, any allied border guards or MPs that the characters would have come into contact with throughout the movie, would also be British and not American.

In the Grand Hotel Potemkin sequence showing the crossed Soviet and East German flags, the East German flag is upside down (black stripe should be on the top); maybe this was a deliberate error on the part of the filmmakers.

In the Grand Hotel Potemkin scene, Peripetchikoff says "We cannot interfere with internal affairs of sovereign Republic of East Germany." The correct formal name of the country was the German Democratic Republic.

When Otto is driving his motorcycle with the balloon attached to the exhaust pipe, the balloon would have popped in a short time from the volume of exhaust gases.

In the shots from the west side of the Brandenburg Gate, a sign is shown reading: "ACHTUNG! YOU ARE NOW LEAVING WEST BERLIN." No such sign, in mixed German and English, was ever posted in Berlin. The signs advising that one was leaving or entering one of the four sectors of the divided city were all written in four languages: German, English, French and Russian. Apart from its factual inaccuracy, it would make no sense to post a sign written partially in one language and partially in another.

At the end of the first verse of "Yes, We Have No Bananas", the orchestra leader stops singing the song and closes his mouth while on the soundtrack his voice continues singing.

When picked up by the East German police, Otto tells them (in German) that he's a member of the Communist Party. While there was an East German communist party, it was not called that, it was the Socialist Unity Party (Sozialistische Einheitspartei Deutschlands, SED) instead. Otto should have said he's a member of the SED or just "the party".

Mrs. MacNamara tells her husband she would like to watch Gunsmoke (1955) in English, implying that in Berlin, she could only watch it in German. Gunsmoke did not start airing in Germany until 1967 however, at least 6 years after the events seen in the film.