Jessica's panties keep changing from light to dark green. In one scene, they appear to be beige.
When Francis jumps down from the balcony, he is obviously headed for a spot at least ten feet from where Logan is standing, but when the shot changes we see him landing directly on Logan.
The cut made by the laser on Logan's shirt runs straight up and down from shoulder to nipple. Later, after destroying Box the cut in the shirt runs from the base of the neck to his armpit at about a 45 degree angle.
Logan and Jessica first see the sun as it rises from behind some distinctive mountain peaks. At the end of their first day, the sun sets behind the very same peaks where it rose. The sunrise seems to be the sunset footage, reversed, which would explain why the sun rises in the wrong direction for Washington, DC.
Jessica's green stockings appear and disappear.
When Logan and Jessica are looking at a large tank, Jessica asks what is. Logan replies "some kind of breeding tank for animals and fish" We can see fish swimming in these tanks.
Later on when they are walking back with the Old Man, Logan says that all the fish died ages ago, yet there are still fish swimming in the tanks.
In the opening prologue the word Carousel is spelled Carrousel. This is simply the original French spelling of the word but this is not a French film nor is it set in France and is therefore a spelling mistake.
When Logan and Jessica find the Old Man she asks to touch his whiskers as if she has never seen a beard before, however the residents of the city aren't killed until they reach 30 and surely most, if not all, of the men have whiskers growing by age 29. She actually asked to touch the "cracks" (wrinkles) on his face.
In the cemetery, Logan and Jessica read the headstones, "beloved wife," and "beloved husband." They've never seen these words before but pronounce them correctly. This might be unlikely with certain words in the English language but "husband" is not difficult to get right for someone who understand the constructs of the language. "Wife" might be a little more difficult, but if they know the words "fife", "rife" and "life", they may have may have just guessed right.
Early on, when Logan fires at the male red runner standing under the archway you can see pyrotechnic special effects props in position on the paved walkway.
At the end of the movie, when the whole domed city is falling apart, big blocks of concrete fall onto some people running in panic, but they just keep running.
In one of the close-ups of Box, you can see his human lips (and his bottom row of teeth) inside the costume while he's talking.
There is a shot looking down the steps of the Lincoln Memorial showing Logan and Jessica climbing the steps. At the right is a column which has been composited into the shot. Less than two minutes later they are shown climbing the steps of the Capitol building. The cut in Logan's shirt has reversed sides because this is a flopped repeat of the earlier shot but without the column.
Toward the end of the film when the city is being destroyed we see a man fall from the 2nd floor. A lit mall "EXIT" sign can be seen behind him.
When the young people cluster around the old man at the very end, one extra can be seen briefly giving the Vulcan hand salute from Star Trek.
The colors corresponding to the characters' ages is inconsistent. Logan says he is a Red 6, and also says he has 4 more years until he reaches 30 - so he is obviously 26 and Red would therefore start at 20. Jessica says she is Green 6 and goes Red next year, so she is presumably 19 and Green would start at 13. However, when she and Logan meet Billy and the cubs, Billy is a yellow and Logan asks him what he's going to do when he turns 16 and goes Green. Additionally, some of the Green characters throughout the film are way too old to be in their teens (or even early 20s).
When Logan is talking to the computer he says "question" but then makes statements, and does not ask a question.
While chatting w Jessica at his flat, Logan alludes to the life-clock turning "black" as being Last-Day.
"Palm Flowers" turn black in the novel, not the film.
In the film, runners have a blinking red life-clock.
About 5 minutes into the movie, Logan and Francis 7 are on the escalator to Carrousel. Logan says "Why were you so angry just then? What did he do to you?" then Francis 7 says "That's red's going to run, I can always tell." Neither of their mouths are moving.
When Logan and Jessica are running away from the New You, Jessica says "We'll have to go through the Love Shop", but her lips aren't moving.
During the hunt for the first runner there were multiple shots where you could see the pyrotechnics on the floor, pillars, and walls. When the runner came around the corner running from Francis and turned to face Logan you could clearly see the pyrotechnic strips on the floor.
In the scene with "Box" in the ice cavern, the film crew can be glimpsed in the reflection of Box's metallic/mirrored body.
When Logan and Francis terminate the first runner near the start of the movie and the "clean up crew" comes to spray/disintegrate the body, the shadow of the wires that hold up the disintegration unit are visible on the wall.
When the citizens are being lifted into the carousel for renewal you can see the wires suspending them.
(at around 8 mins) Strings can be seen rotating with the people slowly floating upward who are partaking in the renewal during Carrousel.
After Logan and Jessica enter Washington, they are seen wading in the reflecting pool on the National Mall, approaching the Washington Monument from the west, with the Capitol visible behind. That would put the Lincoln Memorial behind them. Yet the next scene has them climbing the steps of the Lincoln Memorial they would have just passed.
When they reach the outside world, and see the sun rise for the first time, the sun rises from bottom right to top left. The sun would only do this in the southern hemisphere. The film is clearly set in and around a post apocalyptic Washington DC. Interestingly magnetic north could change, but the direction in which the sun rises, is physically incapable of change.
When Logan and Jessica emerge from the ice cave, they see the sun rising from behind a great mountain. As they make their way to Washington DC, they travel through valleys and mountains to get there. There are no mountains such as these or any other kind even within miles of the vicinity of Washington DC.
The last act established the city as being on the coast (presumably the Atlantic Ocean.) Yet after Logan and Jessica flee the city and travel across the countryside, they approach Washington DC from the west, crossing the Potomac and traveling up the Mall from the Lincoln Memorial to the Capitol.
Logan says that Billy has to leave Cathedral when he goes green. Cathedral is for violent uncontrollable children. Where do violent uncontrollable teenagers go?
It makes little sense that there are such a wide diversity of accents in the city, such as Logan speaking with a heavy Yorkshire accent while Francis speaks as if he were from New York (which is where the actors are actually from). Within a closed environment like the city, everyone should speak the same since there is little to no diversity.
At least two Runners are confronted in Cathedral, which is sealed to contain the violent Cubs. How did they get in?
The city's calendar is apparently based on astrological signs rather than the standard months we use today. The film takes place during the "month" of Capricorn, which is during December and January of a standard year, when it would be bitterly cold outdoors in the Washington DC area. However, the outdoor weather in the film is obviously very mild. (It is possible, however, that the astrological "months" are used during different times of year, or that some type of massive catastrophe occurred that changed the climate.)
When meeting the other Sandman that had been to Cathedral and fought the Cubs, Logan told him to get a new face, so he wouldn't be recognized, later after Logan goes to Cathedral he also goes to New You to change his face. There is no reason for a Sandman to change his face to protect his identity, as they can be identified by their uniform.
When Logan is forced to submit to surrogation by the computer after returning from the outside, he is being guarded by a couple of sandmen. Both men are clearly older than 30 as they have wrinkles.
Jessica, while talking to the old man about his burial, reassures him that his death is a long way off. However, the character had never even seen an old person so would have no idea about a lifespan. She could not have simply been intending to be polite because the city dwellers had no cliches or conventions about natural death.
It is clearly established that sandmen believe runners lose the chance at renewal and are permanently dead. Yet Logan expresses astonishment that no runners are renewed. He should believe that none have ever been renewed.