Crew or equipment visible: Shadow of camera and operator on Derby contestants.
Continuity: When they're 'jogging' around the dance floor, Gloria's shirt is soaked with sweat. The next shot it has only one sweat spot, and in the next it's all drenched again.
Anachronisms: Robert tells Gloria about a film he saw starring Anita Louise and Richard Cromwell in which Anita Louise's character has a brain tumor. However, Louise and Cromwell only made two films together, The Most Precious Thing in Life (1934) and The Villain Still Pursued Her (1940). The depression-era dance marathon, which is the subject of the film, presumably takes place in 1932. Earlier in the movie, we hear Mrs. Layton tell Robert and Gloria that they are her favorite couple because they are number 67, the same year that she was born (1867). Shortly thereafter, Gloria tells Robert that she's figured out Mrs. Layton is 65-years-old. Sixty-five years after 1867 is 1932, which is prior to either of the Louise/Cromwell films.
Anachronisms: The Edward Heyman/Johnny Green song "Easy Come Easy Go", which is used as the film's title theme and is performed by a singer at the fictional dance marathon, was not published until 1934 (two years after the film's 1932 setting).