Factual error: In the drugstore scene where Mary whispers in George's bad ear, there are several shots showing a Coca-Cola thermometer on the wall where George hangs his jacket. This particular scene was to have taken place in 1919, but this particular thermometer wasn't produced until 1939.
Factual error: In the closing scene Ernie the cab driver is wearing a military shirt with an Air Force insignia on the sleeve, but we were told earlier that Ernie parachuted into France. His shirt should have had a different patch.
Factual error: Since it's cold and snowing throughout most of the movie, how come you never see the people's breath? This is because when they filmed these parts, it was very hot outside, but it's still a mistake.
Suggested correction: Seeing a person's breath is not entirely dependent on how cold it is, but rather how much or how little humidity there is in the air.
Seeing your breath is based on how cold it is, however, with high enough relative humidity, you're able to see your breath in warmer temperatures. If it's cold enough to snow, it's cold enough to see your breath, regardless of what the humidity is.
Factual error: When Clarence picks up his copy of "Tom Sawyer" to see if it is dry, the book is in perfect condition, despite their clothes being soaked. The pages of book that had been soaked in water would been swollen and wrinkled, and many pages would very likely have stuck together as the book dried.
