When Gene goes over to his soon to be ex-wife in the club, the ashtray fills up between cuts.
When Gene, Nina and Bill are at the table in the club, discussing the plot for a play, Bill's cigarette keeps changing length.
Sheltering from the rain in the newsstand, the water-stains on the lapels on Nina's coat only appear in her close-up and not before or after that shot.
When the camera pans with Charles Engle as he gets up to leave the poker game, the shadow of a cable dangling from the microphone boom can be seen following him against the back wall.