When Tallahassee walks towards the Hummer the arms attached to the steering wheel are away from the wheel when we first see them, yet in the very next shot they are against, if not tucked inside, the steering wheel.
Early in the film, Columbus enumerates his rules for survival. While he explains rule #4, "Beware of bathrooms", he flees a bathroom at a gas station, with a single male zombie in pursuit. As he rounds a corner, he sees and shoots a female zombie and we see that the male zombie is almost close enough to touch Columbus. In the very next shot, with no apparent time lost between cuts, the male zombie is now much further away.
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.
When Tallahassee and Columbus meet and pull their guns on each other, there are a few cut scenes that show them with their guns raised. A shot is then shown where you see Tallahassee raise his gun again.
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.
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.
When Columbus and Tallahassee are at the Hostess truck Columbus flips a package of snowballs into one hand and the gun is in his other hand. In the following shot the package and gun have traded places.
When Wichita entices Columbus with a bottle of wine, we see Columbus standing near a surface covered in picture frames and knick knacks. When the camera is on him, the vase in the back has a lid that is sitting perfectly flat. The camera switches to Wichita and then back to Columbus who then moves the lid that is now crooked.
When Tallahassee and Columbus are outside the grocery store, Tallahassee is taking out various weapons for destruction, one of them is a baseball bat. As he is talking about the expiration date of the Twinkie you can see there is no weight on the bat (used for practicing your swing as it makes your swing slower). As they enter the store all of a sudden a red weight has been added.
When Tallahassee barricades himself in the game booth at Pacific Playland, he prepares for his gunfight by placing four magazines on the counter in the following order (left to right): One single-stack mag, one double-stack mag, one single-stack, one double-stack. When he runs out of ammo and goes to reload, the magazines have changed order. They are now (left to right) two double-stacks and two single-stacks. Additionally, both guns are empty and he dropped the magazines from both guns, but when he slams the guns down onto the magazines, he only actually reloads one gun. Three mags are left on the counter (one double, two singles).
In the scene where Columbus and Wichata get out the yellow Humvee to collect a map for Beverly Hills stars mansions Columbus shoots a zombie in a pink outfit. The zombie falls dead on the pavement. However when Columbus gets into Humvee in the next shot the zombie in the pink outfit is lying in the street in front of the side door.
When Tallahasse walks towards the Hummer the arms attached to the steering wheel are away from the wheel when we first see them, yet in the very next shot they are against, if not tucked inside, the steering wheel.
When Columbus first meets Tallahassee, they pull their guns on each other. When Tallahassee pulls his gun, he holds it with his left hand. In the long shot, it switches to his right hand. In the closeup, it's back in his left hand.
When Columbus and Tallahassee opened the hostess truck and all the snowballs fell out it caused Tallahassee to get mad and rant about Twinkies and why there were none but from the inside the truck shot you could see a bunch of Twinkies 3 times off to the side behind the 1 closed door.
When Columbus and Wichita are drinking alone and talking in the mansion, the candle lengths of the various candelabras in the background table between their heads vary greatly in size between dialog shots.
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 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.
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 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.
At the beginning of the film, Columbus states that he is making his way from his dorm room in Austin to Columbus. In a later flashback, it is obvious he lives in an apartment, not a dormitory. However, if he is attending school at the University of Texas this is a possible type of housing since the university is not able to support the freshman class in traditional dormitories. Columbus may be living in a housing co-op which could resemble an apartment more than a dormitory
When the party gets to the theme park, they turn the power on in order to ride the rides; however, there are two possible problems with this. On one hand, since nobody is running the power plant, it is unlikely that it would be generating power and on the other hand, it is unlikely that anybody would have had or taken the time to turn off the power in the first place. If it was soon after the zombie apocalypse as implied there may still be electricity for a short while.
When Columbus and Tallahassee are at the Hostess truck and Tallahassee is flipping out because the truck contains Snowballs instead of Twinkies, the two shots from the inside of the truck show that their are indeed Twinkies behind the other door.
Zombies have an increased sense of smell, and can smell if humans are not secreting necromones (pheromones secreted by deceased and decomposing people/animals). Bill Murray has only applied makeup to "blend in", stating that "zombies don't mess with other zombies". The zombies being unable to detect that he isn't a zombie is impossible.
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.
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.
In the introduction, when Columbus is listing the rules, during the "Fasten your seat belt" rule the woman is driving away from a group of small girls in a minivan. The girl who falls from the back of the van wearing the yellow dress is an adult stunt double.
In the opening credits there's a slow motion shot of a man in a bow tie shooting a gun. We can see the empty shells being ejected, but in slow motion it's clear that there are no bullets coming out of the gun.
When Witchita and Little Rock are on the "Blast Off" ride at Pacific Playland, before taking off they shoot the approaching zombies. The last zombie to approach them before launching gets shot, but Witchita and Little Rock do not shoot, or even aim at him.
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.
The goof items below may give away important plot points.
Saluting the late Bill Murray with gunfire, Tallahassee, Columbus and Wichita fire their weapons, but Little Rock does not pull the trigger. It can be clearly seen that she does not pull the trigger yet there is a sound to signify that she has, and she also proceeds to reload her gun three times without pulling the trigger once.
When Columbus and Tallahassee are leaving Bill Murray's house, Columbus is riding away on a motorcycle wearing a leather jacket. He proceeds to crash the bike in the driveway and when Tallahassee drives closer to pick him up Columbus is no longer wearing the leather jacket.
When Little Rock and Wichita go to the amusement park, they leave the mansion in the morning, and arrive when it is dark. However, when Tallahassee and Columbus go after them, they leave in darkness, and arrive in darkness. The girls are still on the ride when they arrive. Tallahassee and Columbus may have driven a lot faster than the girls, and its not implausible that the 2 girls managed to stay alive on the ride for as long as they did, and nothing suggests that the guys arrive much later than the girls
When Columbus goes to save Wichita and Little Rock, who are stuck on a ride, he is faced with a clown. He checks his pockets and pulls out two shells in a zip-lock bag. He drops them and does not have time to reload. However, he has had time to reload before the next scene in which he shoots the Twinkies.
Tallahassee says there are six people alive in the world when he meets Bill Murray. Outside of flashbacks, there are only five live people in the movie - Columbus, Tallahassee, Wichita, Little Rock and Murray. However, Cynthia Knickerbocker earned Zombie Kill of the Week about halfway through the movie, which brings the count to six living people even though there are only five alive in the party. In addition, Tallahassee may have simply been paraphrasing; unless he checked every square inch of the planet, there's no way he could know exactly how many people were still alive in the world.