Harriet Monroe is shown raking leaves in her yard, but all the trees around her have green leaves, because the filming was done in July.
During defense testimony, a character witness testifies to holding several World War I decorations, such as the Silver Star, Purple Heart, and Bronze Star with oak leaf cluster. None of these awards were in existence in the 1920s when the film is set (the Silver Star and Purple Heart were first issued in 1932). In the case of the Bronze Star, the medal did not exist until 1944.
In the opening scene, David Stevenson in seen driving down a gravel road in a 1920's vintage car. (The movie is set in 1925) if one looks off to the left of his car they will clearly see a modern day pickup and horse trailer sitting on the road halfway in the frame.