Continuity mistake: When the milkman is drinking milk in the bar and talking to the Tony the Tiger actor, the amount of milk in his glass changes with the different camera angles. It goes from 2/3 full to mostly full to half full back to mostly full. (00:54:56 - 00:55:45)
Factual error: Someone shouts "jobsworth" at a London Underground official. This term is first recorded in 1970. The film is set in 1940.