Continuity mistake: In the film's final scenes at the fuel storage facility, full sunlight is streaming through the overhead rafters. Moments later, it's completely dark and the plant's floodlights are all turned on. A few shots further on, the lights are off and it's daylight again.
Continuity mistake: When the butler tells of Harry Lime's death, at the start of the conversation he can hardly speak English. As the conversation goes on, his English gets better and better, until at the end it's perfect with just an accent.
Suggested correction: He is reluctant to speak English at the start possibly to avoid trouble but later decides otherwise.