Deliberate mistake: During the sting attempt towards the beginning, Douglas confronts Snyder on the roof of the building. A helicopter rises up from nowhere without making any sound prior to that.
Deliberate mistake: When David brings Jack home to meet the family and at the beginning of Santa Fe number.It starts raining buckets during dinner and the cake scene, but less than a minute passes and it is dry enough to sit down on the stairs at the beginning of the Santa Fe number. Then during the song "Santa Fe" and later in the dance sequence, the ground is dry as Jack is kicking up dust.
Deliberate mistake: When Jafar sees Aladdin reflected in Jasmine's crown, Aladdin is the only thing visible. This isn't possible- we should have also seen the background of the room, the objects around him, etc.
Deliberate mistake: Gonzo and Rizzo are selling apples in the beginning, including the Red Delicious cultivar. That wasn't invented until the 1880s and the story is set sometime in the first half of the 1800s. Most likely intentional as they are the narrators.
Deliberate mistake: When Marge and Dick are being beamed in outer space, there's no way they could be breathing because there's no breathable air in space.