Deliberate mistake: When the family first entry Three Chimneys they have a single lamp as a light source. Entering from the door at the rear of the shot, everything in front of them should be in darkness to the viewer, but it's lit. Things in the background are lit even though there would be no line of sight to the light source. This is because lighting was added on set to allow the viewer to see things better, even though it ruined the realism.
Deliberate mistake: At the end, there is no way that the RV managed to roll over and flatten the vehicles in its path.
Deliberate mistake: While roasting marshmallows, Henry's marshmallow caught on fire with the flame shooting about 6", then a foot+ high. A marshmallow subjected to such intense heat/flame for many seconds would not be stuck to the stick and stay stuck with repeated forceful flicking or "whipping" of the stick like Henry did. When the marshmallow finally flew off the stick and landed on a camper's head (higher than would be expected), it would be small/hard/charred, not large and still soft/white in the middle. (00:35:03)
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: 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: When C-3PO, R2-D2 and the younglings are driving through the battle zone, Anakin Skywalker and General Grevious can be seen battling. Later, Darth Vader can be seen on Hoth. This would be impossible due to Anakin Skywalker being Darth Vader. (00:08:50 - 00:12:20)
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: For an unknown amount of time during the family's four-day road trip, a Spanish tutorial cassette or CD was played. This would not be enough time for anyone to be able to fluently speak Spanish or carry on a conversation, but toddler Manny was able to do so near the end of the movie.
Deliberate mistake: In multiple shots, Stitch's ear notches move higher in places or vanish completely.
Deliberate mistake: In the scene where Marmaduke runs over Don Towmbly, you can "see" the soft mat where he lands on his face: it wobbles.
Deliberate mistake: In the housing block that Dave's house is in, the house numbers do not match - because In one shot of Claire walking past Dave's house, you can see that the house numbers are in the 1500's - one homes number is clearly 1516. However Dave's house number is 1958. However this is a deliberate mistake as the 1958 on Dave's house is a reference to when the Chipmunk fever was born. (00:23:50 - 00:32:35)
Deliberate mistake: When Alice is about to meet the queen she hides the brush covered in red paint under her dress. The brush later disappears plus Alice doesn't have any stains on her clothes.
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: There was a black wrought iron fence behind Whitney but with enough space for JD to drive between them. After JD parked, Whitney (and her friend) were much closer to the fence, but they were also at the rear of JD's parked SUV, which would not be spatially possible. When JD, Jane, and Ally got out of the SUV, they walked right in front of Whitney, who was now much closer, and the fence was no longer behind Whitney. (00:27:50 - 00:28:14)
Deliberate mistake: When Casey is hiding behind the boxes waiting to knock out a Foot soldier and steal his outfit, you can see he is still wearing his denim vest. After he knocks out the Foot soldier, he is able to put on his entire outfit in roughly three seconds. (01:10:15)