Revealing mistake: When Sassy comes out of the burning house carrying the kitten in her mouth you can tell that the kitten is fake.
Revealing mistake: At the start of the montage in which Frollo ransacks Paris for the gypsy girl, the shot of the three soldiers kicking down the baker's door very briefly places the more distant soldier off to the right "in front" of the closer central soldier; this is a case of incorrect animation cel layering.
Revealing mistake: When Diana is about to jump off the plane onto the galloping horse, her hair moves wildly. When the shot changes, she has been replaced by a stunt who looks nothing like her and has her hair fixed.