In the film, Helen Morgan never married; the real Helen Morgan married three times.
When Larry robs the liquor warehouse, he pulls out a crate at the top of a stack. The crate directly beneath it partially pulls out under it and tilts down slightly. If the case were filled with full liquor bottles, as it supposedly would have been, it would have been too heavy to have moved in this way.
Paul Newman's character, Larry Maddux, repeatedly refers to Florenz Ziegfeld as "Ziegfield." All the other characters say Ziegfeld's name correctly.