Early in the film when Gerald Clamson (Jerry Lewis) is pushing the sailboat into the water, he ends up hanging over the water with his hands on the boat and his feet on the dock, and then falls in. Before he falls into the water, Gerald's pants are white, but when he clambers back onto the dock a moment later, his pants are blue.
The edges of the bald cap "wig" worn by Mr. Fong (Leonard Stone) are occasionally quite visible, particularly during closeups.
Jerry Lewis's character appears married and wearing a wedding band on his left 4th finger in 16:00 min, but pursues romantic encounters with others in rest of the movie. [contributed by M. Neshat]