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: When the camera pans to the theatre right after the opening credits, the sign uses the British spelling of "theatre" instead of the American "theater."