1950s cars visible in some scenes, even though the film is set in the 1920s and 1930s. In the overhead shot looking down at the Casino, the painted white lanes in the roadway and all the cars driving by are strictly contemporary 1950s.
Duchin's wife died on August 3, 1937, not at Christmas as depicted in the movie. In the next sequence, five years is supposed to have passed, and Duchin reads about the evacuation of Dunkirk in the newspaper, which took place in May-June 1940, so that would move the date of Marjorie's death (and Peter's birth) back to at least December 1935, which fails to coincide with the actual true information.
Eddy Duchin suffered from acute myelogenous leukemia. This blood disease would not have created the hand paralysis shown in the movie. The paralysis was done for dramatic effect. Eddy Duchin died at Memorial Hospital in New York City on February 9, 1951. He was 41.
The goof items below may give away important plot points.
Errors in geography
When Eddy walks out of his house after learning he's dying, he turns right, heading east. Chiquita follows him out a few seconds later, looks left, then right, and catches sight of him as the film cuts to Eddy walking up onto a pedestrian overpass on the East River Drive (today's FDR Drive). Duchin's mansion is at the corner of Fifth Avenue in Manhattan, and the East River Drive is 9 or 10 blocks away, a distance of approximately two miles. It would be impossible for Chiquita, standing outside the mansion, to see Eddy walking by the East River Drive from that distance - let alone for either of them to have walked that distance in the few seconds depicted in the film.
It is Christmas time when Eddy goes and sees his wife Margorie in the hospital shortly after giving birth to their son Peter and 6 days later Margorie passing away. Peter was born July 28, and Margorie died on August 3.