When Tallahassee is in the game booth you can see the zombies opening the gate on one side, but in the next shot it's closed.
When Columbus shoots the Twinkies at the end of the movie, there are a couple Twinkies by Tallahassee's shoulder when he enters the closet. Before he enters there are some in a box above the destroyed box, which are replaced by Blow Pops in the next shot.
When Tallahassee paints the number "3" on the driver's door of the Hummer, the number changes size later in the film and all additional shots.
When Columbus first sees the black Escalade coming down the highway, Tallahassee rams a car out of the way, the 'bulldozer' attachment on the bumper gets damaged, then seconds later, it is back the way it was.
In the first scene with Columbus when he fiddles with the keys trying to get his car door unlocked while being chased by zombies, when he decides to take them for another lap he drops the keys on the ground however when he is running away we can see that there are no keys on the ground.
The first ride that Wichita and Little Rock ride at Pacific Playland requires an attendant to be present to hold down an "operator present" button for the ride to function. If no one is at the park to operate the ride, then the girls would not be able to ride it.
'Remember Mad Cow Disease?' explains the protagonist. 'Well, Mad Cow became Mad Person, became Mad Zombie. It's a fast-acting virus' => Mad Cow Disease is caused by proteins called prions, which can definitely not develop into a virus since they do not have DNA, RNA or any other sort of nucleic acid.
When Wichita and Little Rock first turn on the power at the amusement park, they turn on the breakers in a main building and it turns on everything. Amusement parks would have breakers at each of the rides for safety reasons. The roller coasters and the other rides would not have started working until someone either turned on the power at the ride OR they started the ride.
While travelling on foot through an unnamed town after their Escalade is stolen, Columbus and Tallahassee pass in front of an abandoned Chieftain tank. Chieftains are British tanks not used by the United States military, and therefore one should not be in an American town.
When Columbus shoots through the door, his buckshot goes through the door and obliterates the Twinkie box, ruining all the Twinkies for Tallahassee. This wouldn't happen given the distance and the shot going through the door.
At the amusement park, as soon as one of the breakers is turned on, the roller coaster lights up and a car goes flying down the track. It would have had to have been pulled up the hill first before being able to go down the track. If the amusement park was shut down in a hurry the power may have gone off while the car may still be at the top.
When Tallahassee manages to grab his gun from Little Rock, Wichita threatens him with a pistol. Where she got it, and why she never uses it before or after this scene is unexplained. Wichita got a gun from the gun supply in the back of the car.
When the girls run to get on the tower of terror ride the harnesses are up on three seats. When the ride starts to rise all three harnesses are down, including the harness on the empty seat. All harnesses must be down for most rides to run.
When Tallahasee and Columbus are in the supermarket, Tallahasee kills a zombie with a banjo. In the next shot of him he is holding what appears to be a metal pipe and the banjo has gone.
However, the "metal pipe" is an aluminum baseball bat. Tallahassee is seen with the bat prior to playing the banjo. After killing the first zombie with the banjo, he switches to the bat. Then switches to the pruning sheers before killing the third zombie. It's clear that he uses each weapon only once, then changes each time.
When Wichita and Little Rock go to the amusement park they proceed to turn on all the lights and go to rides they put them in very exposed situations. Considering all that they have been through, they wouldn't have continued to go on the rides until they cleaned out the park. Wichita has been telling her sister that there are no zombies in Playland, there fore suggesting they clear zombies out would expose her lie and the sister would see no reason for it.
Throughout the movie, shotguns are fired on numerous occasions with no recoil. This is especially noticeable at the amusement park when the girls are both firing from the hip.
When Tallahassee and Columbus push the stand, creating a domino effect with the other stands, the last stand is seen to be falling before it had contact with the one before it.
After the first meeting of Columbus and Tallahassee, there are already well-worn tire tracks that they follow, indicating multiple takes.
In the grocery store when Wichita checks the double barrel shotgun to see if it's loaded, firing pin indentations are visible in the primers of the shells indicating the shells have already been fired.
When Tallahassee is destroying the minivan with a crowbar, he proceeds to smash out all the windows. When he smashes the rear windshield, there is a brief moment (1 or 2 frames) where you can see his prop crowbar break in half.
When Tallahassee teaches Little Rock how to shoot, there is no audio for when Little Rock reloads her gun, and an empty shell hits the ground.
When Tallahassee is showing Little Rock how to shoot, she pulls the trigger, the hammer clicks, the camera cuts to the other side, and the gunfire noise is made.
When Tallahassee finds the yellow hummer, he opens the driver's door and the camera is visible in the mirror.
In the scene in which zombies climb the Tower of Terror-style ride to get Wichita and Little Rock, a safety harness is briefly visible on one of the male zombies.
When Tallahassee smashes out the windows on the car in front of the store, a man in a suit can be seen moving behind the posters in the window.
When Columbus and Tallahassee first get the Hummer, the road that they are seen driving on in Texas is the same road the entire group is seen driving on just as the pass the sign that says "Welcome to California."
The film takes place 2 months after the first zombie attacks, but still we see a functioning power grid and electricity everywhere. This is highly unlikely without human supervision.
When the girls are riding the swinging ship at the amusement park, they suddenly see zombies mere yards away from them. In the next shot, you see them running away to get to the Hummer. Based on the speed the ride was swinging, and the speed the zombies were running, there is no way the girls could have stopped it quickly enough for them to escape.
Columbus has the rule that you must shoot each zombie twice, and even though he has ready access to high capacity weapons that can be quickly reloaded, he chooses to only carry a double-barreled shotgun, meaning he is nearly killed numerous times because his gun is useless after just two shots.
Wichita claims she ran out of shells during the climax, however her side saddle shell holder clearly was shown holding a few shells and she had plenty of time to reload with them.
At nearly the very end of the movie, Wichita is trying to locate the group member nicknamed "Tallahassee;" however, she mistakenly asks the question, "Where is 'Florida?'"
Columbus refers to a "serious," "tour de France" bike as having toe clips. This isn't true as such cyclists use cleats that snap them into a connection with the pedals at the sole.
The characters go by the names of the places of where they are from. Yet, Wichita refers to Little Rock as her sister.