Deliberate mistake: Throughout the whole short film, Geri's hair doesn't move or react to anything (such as the wind or his glasses). The glasses even seem to go through his hair without any movement in his hair. (00:01:00 - 00:03:35)
Deliberate mistake: When the Darlings discover the dead rat, they raise the curtain and cry out loud, but the rat is nowhere to be seen. Given Disney's long time history of refusals to show dead bodies or blood, it's highly possible that this was a deliberate mistake, but really awkward indeed.
Deliberate mistake: Paddington puts a red sock in the load of prison clothes which turns all their clothes pink. However, it was a single red sock in the "uniforms" machine, but in the next scene the entire prison is wearing pink clothes now. The machine is nowhere near big enough to wash all the uniforms at once - the pile we see is huge.
Deliberate mistake: During "Nobody Cares Like a Bear," Kim opens a gift box containing a balloon. Secret Bear then grabs it and floats away. But when Grumpy Bear tosses a star and pops the balloon, confetti flies out of it and, for the next second, keeps reappearing from nowhere. (00:14:05)
Deliberate mistake: Rocks on the water suddenly appear when the rabbit shows up, which allow for Alice to chase him.
Deliberate mistake: When young Odette is sliding down the banister, and gets stuck spinning around the end of it, it would be impossible to spin like that without her legs hitting the rail that she just slid down.
Deliberate mistake: Several times during the movie the narrator explains what happens while the book flips its pages. During this, every page is identical to the last one so the animation has simply been copied/reused to save time and money.
Deliberate mistake: In the Spanish release, the name of the family store is written in Spanish, but inside the place it's in English everywhere. This is a very common mistake in foreign kids' films released in Spain.
Deliberate mistake: In multiple shots, Stitch's ear notches move higher in places or vanish completely.
Deliberate mistake: In the Swedish dub, they euphemistically replace the words "execution" with "punishment."