Factual error: When Premier Kamenev shows Kiril a map over the Chinese-Soviet border, it shows the Korean peninsula as a part of China.
Continuity mistake: Throughout the movie, Alan Arkin is carrying in his breast pocket a Cross Chrome pen to write messages with on his pad. (He is a deaf mute.) But in the scene where he is on the porch with Sondra Locke and he is drawing a picture for her, he pulls that pen out of his pocket, yet when the scene cuts to a different angle showing him actually drawing on his pad, it is a thick, black felt tip pen. (01:25:00)
Continuity mistake: The ford transit van used by the demolition men Ron and Mr Perry changes between scenes from a long wheelbase van reg no. KGX107D to a standard van reg no. OYO576F.
Continuity mistake: The girl named Why is in the bathtub. Frédérique brought her a cup of tea that she indignantly put aside because it had an excess 1/2 sugarcube. She put the cup to the edge of the tub with the spoon facing one direction, but during the conversation the spoon turns 180° on its own during a cut. (00:07:40)
Revealing mistake: When Buck and the gang ride away from the saloon in Dallas where JC made a few new 'friends', the footage is sped-up for a second just as soon as James Caan jumps on his horse. (00:05:50)
Continuity mistake: When Matt and Freya are in the car chase, the driver's side of Matt's car is badly damaged. After escaping their pursuers, they drive off (in the same car) and return to Copenhagen. When Matt pulls into town, the side of the car is intact again.