When Joe rows the doctor across the stormy waters, the doctor upbraids him for getting him out of bed under false pretenses. In answer, Joe sings a line from "Ah Still Suits Me", but his lip movements don't quite match the sound of his voice.
About five minutes in, Cap'n Andy Hawks is introducing Miss Ellie May Chipley, the toast of Cairo, Illinois. He mispronounces Cairo. His pronunciation is for the capital of Egypt. Cairo, IL is pronounced Kay'ro, with perhaps other local variants. But NEVER as the Egyptian capital.
At one point in the story, Cap'n Andy and Parthy discuss hiring a new leading man and leading lady. Just before Cap'n Andy says, "But where do we go from here? We can't give no more shows without a leading man !" he and Parthy are abruptly seen in a slightly different position.
When Ravenal first meets Magnolia, just after he sings "Where's The Mate For Me?", she mentions that she plays the piano. He asks, "Was that you I heard just now?", but there is no indication in the film that he actually has heard her. This is probably because part of the scene may have been edited out before the film's release. In the original show, Ravenal sings the first verse of "Where's The Mate For Me?", and then hears Magnolia practicing offstage. Then he goes on to sing a part of the song which is not included in the film. Immediately afterwards, his first conversation with Magnolia takes place, and so, in the stage version, the audience knows exactly when he heard her practicing.
When Joe begins to sing "Ol' Man River" he picks up a board and begins to whittle it. He slices off two pieces and then the camera switches to an oblique shot. But now the board is whittled to a slender rod.
During the scene in which Cap'n Andy introduces his actors to the crowd, a young woman looks off to the side absent-mindedly as the captain begins to introduce Ellie. As soon as he mentions Ellie's name, the young woman seems to snap to attention and automatically smiles broadly and gives out a loud cheer along with the rest of the crowd.