Continuity mistake: When Bernard and Bianca arrive at the airport, and wait for Orville, Bianca removes her coat. Yet when we see her through the window, her coat has reappeared and it then vanishes again. (00:25:15)
Continuity mistake: Orville the albatross flies the mice with a sardine can attached to his back, however, when he lands at Devil's Bayou, the sardine can disappears after he is hit by Mr. Snoops' fireworks. (00:34:05)
Continuity mistake: As Penny sneaks off, Brutus and Nero have collars on, with chains attached to the right side of their necks. In a reverse shot the chains are attached to the left side of their neck. (00:00:40)
Continuity mistake: When Bernard and Bianca arrive at the airport, they have a suitcase each. They get on the escaltor with the two suitcases, nothing else. Then when they arrive at the top of the escaltor, Bianca now has a pink handbag on her shoulder. (00:23:10)
Continuity mistake: The message from the bottle, written by Penny, has a couple of mistakes. When it falls from the bottle the writing is several inches from the top of the paper and part of the letter says "New York." When it cuts, the writing on the letter starts right near the top of the paper, and it now reads "New Yorc." Also between different shots, the writing on the note changes from being written in cursive to printed. (00:08:45)
Continuity mistake: When Nero and Brutus bring Penny back, they walk through two double doors, one of which is broken, and off its hinges. They are left open, yet when Medusa enters, she walks through the same doors. Not only are they now closed, but the one which was off its hinges is now fixed back on. (00:41:00 - 00:42:00)
Continuity mistake: The two alligators catch Penny and bring her back to the house. They approach Snoops, scaring him. One of the alligators still has the Penny's Teddy Bear in it's mouth. In the next shot, Penny is holding her Teddy. (00:40:50)
Continuity mistake: As Medusa packs her bag, between shots an elastic clip appears, hanging out of the case. (00:21:30)
Continuity mistake: Bianca's seatbelt disappears for one shot, as they sit in the sardine can, before taking off. (00:27:15)
Continuity mistake: After Medusa has spoken to Snoops on the phone, the phone vanishes from the desk in order for Medusa to put her suitcase down on it. (00:21:10)
Continuity mistake: After Rufus tells Bernard and Bianca about Penny, the lantern on the paint can beside Bernard vanishes then reappears. (00:18:05)
Continuity mistake: When Bernard and Bianca are waiting for Orville in the airport room, the direction that the volume button on the speaker points keeps changing. (00:24:50)
Continuity mistake: As the coloured man walks towards the United Nations building, he is wearing a red turban, but as he enters the building, his turban is now a fez. (00:04:30)
Continuity mistake: When Bernard and Bianca go to the orphanage, they rummage through a box labelled "Penny", then Rufus finds them and they talk. As Bianca and Bernard climb from out of the box, as Bernard stands on the cardboard flap, his hands are empty. It cuts and now the lantern has appeared in his hand. (00:14:55)
Continuity mistake: Orville is flying, when he's hit by flares. As he goes down, his chinstrap is suddenly undone. When he crashes, it's buckled again. (00:34:00)
Continuity mistake: After Medusa flies off on her motorboat, to find Penny, her headlight that is attached to the left side of the windshield frame disappears for a shot. (00:33:05)
Continuity mistake: The Latvian and French mice in the Rescue Aid Society are in two different locations between shots. (00:06:25)
Continuity mistake: We see a group of mice walking towards the entrance to the Rescue Aid Society. Bernard is sweeping by the entrance. Two mice are just about to enter. In the next shot, the two mice are gone. (00:05:20)
Continuity mistake: After Orville lands on his runway, as he talks to Bianca and Bernard, his chin strap goes from buckled to unbuckled between different shots. (00:25:55)
Continuity mistake: The headlight that is attached to the left side of the windshield frame on Medusa's motorboat, jumps to being on the right side of the frame for a shot, after the female mouse says she'd like to hit Medusa with her rolling pin. (00:37:20)
Chosen answer: She may have been very upset with Penny for running away. But she may have also had a talk with her like she does much later in the movie about why she needs her for finding the diamond.