During the battle between the Nutcracker and the Mouse King, Clara takes off her slipper and throws it at the Mouse King, in order to stop him from killing the Nutcracker. Moments later, however, she is seen backing up and both slippers are on her feet.
When Uncle Drosselmeyer tells Clara that Drosselmeyer had decided that the time had come to invent the Mouse Trap Nutcracker has all of his teeth. After Uncle Drosselmeyer finishes his story Nutcracker is missing his two front teeth again.
When Fritz is shown preparing for battle only seconds after Clara was shown in full figure dancing in her new, pink slippers, they are replaced with dark, strapped shoes in the following full figure shot.
When Hans gives Princess Pirlipat the Krakatooth Nut his eyes aren't closed.
When Clara is comforting Pavlova as she's leaving for the Land of the Dolls his collar is gone. In the next shot Pavlova's collar is back.
When Clara, the Nutcracker and the others enter the Gingerbread Castle, there's a bunch of static background figures with only a handful of barely animated ones, all of whose cheering voices don't match with them in the shot.
There's one shot where Clara takes Pantaloon's sword to give it to the Nutcracker and Pantaloon stutters in protest. In the next shot, Pantaloon stopped moving while his voice is still heard saying the rest of his words.
When the Mouse King orders Clara to hand over the Nutcracker, Clara's lips don't move the second time she says "no" to him.