Continuity mistake: After Bugs shoots the man in the audience for coughing, the style of notes in the music book in front of him changes between shots.
Continuity mistake: When Bugs begins his performance, he takes a carrot from the far end of the piano, takes a bite out of it and puts it back. When we see Bugs performing a couple of shots later, the carrot has disappeared.
Continuity mistake: When Bugs is turning the pages of his piano book, he sees a woman in a bikini and then carries on turning until he gets to the right page. When he gets to the right page, the style of the notes changes between shots.