Deliberate mistake: As the Soviet tank starts rolling, the tank commander obviously uses a hidden step to mount the tank. Soviet T-55/T-62 type tanks did not have steps for mounting by the wheels and axles; to mount a rolling tank using the moving wheels or spinning axles would result in the mounter being immediately crushed and killed.
Factual error: The movie takes place during the year 1919. Yet before one of the World Series games the stadium announcer requests that everyone stand up to sing "the national anthem". The US did not have a national anthem until the 1930's when Frankin D. Rosevelt signed into law the Star Spangled Banner as the nation anthem.
Suggested correction: According to Ken Burn's "Baseball", Burns and Ward verify that "The Star Spangled Banner" was sung at a baseball game in 1918 to support the efforts of American Troops in WWI- in which players like Ty Cobb, George Sistler, and Christy Mathewson all fought.
The mistake is saying the announcer called it the national anthem, not that they sung "The Star Spangled Banner."
Continuity mistake: The actress loads her 35mm Praktica camera with Kodak film. That's not really strange, but the film is situated in 1968 around the invasion of the Russians in Prague. The film cassette is clearly visible as having DX coding on one side for setting the film speed automatically. This feature had yet to be invented in 1968, because it was released in the early 80's.