Deliberate mistake: Rocks on the water suddenly appear when the rabbit shows up, which allow for Alice to chase him.
Deliberate mistake: In the fire scene, Jon tries to catch Garfield from the chandelier at the main staircase. When Jon reaches out to grab Garfield, there is no rail on the stairs. It comes back in the very next shot & disappears again after Garfield says "Need a lift?"
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: 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: At the end of the film, when Alex, Maggie and Grig take off in the Gunstar, the crowd of trailer park residents watching them leave backs into the covered portion of the restaurant, right next to the 'Starfighter' game cabinet, which is readily visible in the shot. Mrs. Rogan then wonders where her younger son, Louis, is. The shot changes to show Louis pulling a bench up to the 'Starfighter' game to play it as dust from the Gunstar liftoff kicks up next to him while he watches it fly. Yet the crowd is nowhere to be seen in the shot of Louis playing the game despite everyone being huddled right next to it on the patio (his mother was standing next to it and should be able to see him). Given the proximity of the crowd to the game a moment earlier, Louis wouldn't be able to play it, let alone put a bench next to it. It's clear the filmmakers chose the image of the younger kid aspiring to be like his brother by playing the game over the logic of where the game was in relation to the crowd.
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: Elizabeth will not be able to save Mateo from falling backwards into the fire pit by grabbing his hand or pulling him back after his whole body is suspended over the edge. (01:13:47)
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)
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: 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: When Max knocks out Jeff with a pool ball, he later wakes up with a VR headset on his face, and he is able to see his body and the outfit he is wearing within the VR environment. This is very obviously not how VR works - you are not able to see your own body while in VR, just the environment you're in. This might have been done deliberately so that Jeff was able to see his movements, but it's still a mistake. (01:05:10)
Deliberate mistake: The prisoners in the dark dungeon would not be able to read the letter (to Miss Dudley from Jason Flemyng that the carrier pigeon had) or see such a clear reflection by pouring water on the stone floor and holding the letter (written backwards) by the water. The room was suddenly lighter when doing so, but it wasn't clear where the light was coming from. Also, sunlight coming through the small window would not beam straight down along the wall. (00:07:23)
Deliberate mistake: Directly after Nicola has her baby, she sits up and holds a baby that is clean, umbilical cord-free, and has teeth. There is no possible way this could happen.
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: At the end, there is no way that the RV managed to roll over and flatten the vehicles in its path.
Deliberate mistake: Puppy Clifford engaged in a "tug-of-war" with a Rock Dove over a French fry and the Rock Dove WON, yanking away the French fry. Overlooking for the present purposes that the French fry did not even appear to be into animated Clifford's mouth, a Dove weighing maybe 13 ounces is no match for even a 5-pound puppy. Clifford probably weighed closer to 10-15. (00:10:40)
Deliberate mistake: Near the end, after the case is dismissed, people are celebrating, and we see a reporter talking, with snow flying around him. Cut to another shot of people watching a television. The snow has disappeared from the reporter's shot. It's likely that, since the snow was added in post, the filmmakers forgot to include it in that one shot.
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.