When Elmer Fudd exclaims he is out of bullets he is shown firing his gun later without reloading it.
Bugs' green flippers and Daffy's rabbit tail disappear when Bugs gets the book on ways to cook a duck.
When Bugs argues to Elmer Fudd that there are other sports besides hunting, Daffy appears in a tennis outfit and a racket saying "Anyone for Tennis?" In one hand he has a tennis racket but if you look at his other hand, his fingers are spread apart as if he was supposed to be holding a tennis ball but the animators possibly forgot to draw one in his hand.
When Elmer says, "Uh oh", his mouth doesn't move.