During the Battle scene when all the Leroys begin to over power the other experiments, one of them fires at Clyde (one of the criminal experiments couple (Bonnie and Clyde)) and knocks him over, Bonnie wrongly calls him by her name instead of his when she goes to attend to him.
Tickle-Tummy, an experiment who was previously seen in Lilo & Stitch: The Series, was accidentally left out of the list of experiments seen in the closing credits. Some fans believed that she was the unseen Experiment 628 until executive producer Jess Winfield later stated that she was mistakenly forgotten. In the credits, her experiment number (275) was taken by "Mamf", who never appeared in the franchise.
At the end of the movie, after Lilo gets a photograph of her and all of her ohana (including the experiments) she puts it into the book which contains the pictures of all the experiments. The other photographs appear to be normal, but earlier on in the movie, Leroy tore an X in each picture as he caught the experiments.