When Napoleon is waiting in the van for Uncle Rico to take him to the dance, he looks at his watch. The time and date displayed is 5:40 p.m., Thursday 7/17. (They may have forgotten to change the date on the watch -- how many school dances are in July?) After he starts running down the road, he stops to look at his watch and the time and date says 5:54 p.m., Monday, 7/21.
After Napoleon drops off the picture at Trisha's house, he runs onto the lawn. But when Trisha's mom closes the glass door, his reflection can be seen still on the porch.
When Lyle is just about to shoot the cow and the school bus moves in front, there are no kids in the bus. But in the next shot, there are.
When Naploeon calls home to ask Kip to bring him his Chap Stick, the position of the nacho's, and the amount of cheese on them changes several times.
When Pedro first places the cake at Summer's door, it has a note under the edge. The shot after the doorbell is rung does not include the note. When Summer opens the door, the note can be seen.
When Kip asks Napoleon to pull him into town, he's lacing up a pair of Rollerblades. However, the opening shot of the movie with the action figure thrown out the bus window establishes that Napoleon & Kip live on a gravel road. Kip would be unable to use his Rollerblades on their gravel road.
In this movie, they are attending high school. However, the playground has an elementary school swing set and other children's equipment. This was most likely done on purpose though since with ruling everything else out, the crew would have presumably known the locations of the production where they were filming.
When Napoleon talks in front of his class in school about a current event he states "Lake Loch Ness". Loch is the Irish, Scottish Gaelic and Scots word for lake. Essentially calling it Lake Lake Ness. This, however, could have been intentional for comedic purposes.
When Napoleon asks if there is anything to eat, Grandma tells him to "make himself a dang quesadilla." She pronounces it wrong - it's supposed to be pronounced "kay-sa-dee-ya." However, this was intentional.
When Rex is using Kip as a demonstration at Rex-Kwon-Do, Napoleon can be seen in the mirror's reflection struggling to keep a straight face.
When Uncle Rico throws a steak at Napoleon, stains can be seen on his clothing from previous takes.
When the farmer shoots the cow, the school bus drives past him. In the shot where the kids scream, the background behind them does not move even though the bus is heard moving.
When Uncle Rico is eating steak on the porch and talking with Kip, it is obvious that he spits out the steak that he had been chewing into the paper towel tucked into his shirt.
When Pedro jumps off the ramp with his bike, you can clearly see at least 3 blocks holding the ramp up, including one in the middle. When Napoleon jumps it, the middle block is missing so that the ramp will break.
When Napoleon is calling Pedro after telling Rico to leave, he dials seven numbers, but you only hear the sound for six of them.
When Napoleon is in front of the class doing Sign Language to the song "The Rose", none of the signs match the words being sung except the first line. They are signing lines from later on in the song.
In the opening credits, several plates are being set down onto carpet; however, all the sound effects are of plates being set onto a wood table or other hard surface.
When Napoleon throws the fruit at Uncle Rico's truck, they are talking but there is no audio.
When Deb calls Napoleon on the pay phone, a crew member's leg is reflected in the silver part of the phone.
When Napoleon is watching Lyle shoot the cow and the bus drives in between them, the camera, tripod, and several members of the crew can be seen reflected in the glass on the bus door.
Cameraman's reflection is visible on Trisha's front door when Napoleon picks her up for the dance.
In the scene following Pedro's scolding from the principal regarding the Piñata, and Pedro and Deb are chatting on the steps - a crew member wearing jeans and a white t-shirt is clearly reflected in the glass doors behind them.
When Uncle Rico pulls up in front of school as Napoleon draws a Liger, a person can be seen running left out of frame. Also, the crew is reflected in the windows.
The credits state that the entire movie was filmed in Idaho but the bus station and Big J's restaurant scenes were filmed in Utah.
Just before Grandma leaves, she tells Napoleon and Kip that she will be back the next day. The audience can see that there is a yellow teddy bear magnet on the refrigerator with nothing underneath it. The very next day, when Napoleon gets home from school, there is a note on the refrigerator that reads, "Napoleon, Don't forget to feed Tina. Love, Grandma :-)" By this time, Grandma has already had her accident and was in the hospital, which means that she never would have had the opportunity to come home and leave the note on the refrigerator.
When Napoleon is outside talking to Pedro's mother on the telephone, the boom microphone is reflected in the one of the door's windows.
At the dance a boom shadow pointing upwards is visible across the students' faces when the camera pans across room.
At the FFA contest none of the FFA members or judges are wearing their jackets zipped up, FFA rules require jackets to be worn zipped to the top.
When Napoleon shows Pedro the picture of the woman that Deb gave him, Pedro says, "I like her bangs." However, the woman in the picture doesn't have bangs.
Official dress of the National FFA organization calls for males to wear black slacks. When shown in the FFA hall, Napoleon is wearing blue jeans.