After Samuel shoots himself, Creasy's Glock is lying on the floor locked in an "open" position, which happens after the last round is fired. However, this would only happen if the gun had the magazine in it, which Creasy removed prior to giving the gun to Samuel.
After Pita is kidnapped, the police chief gives her full name as "Pita Martin Ramos". Not only is the child's real first name "Lupita," but according to Mexican name customs, the father's surname should go first, making it "Lupita Ramos Martin".
When Creasy is standing on the bridge before taking his final walk, there is a shot which shows his St. Jude medallion hanging visibly outside his shirt, but after a cut-away, he is next shown pulling the medallion out.
At the bottom of the cliff, a guy in a lab coat is walking around with a clipboard, a fireman appears to be putting _up_ a fire hose, and Jorge Gonzales' car is attached to a tow truck, all happening while the car is still burning. The behavior of the lab coat guy and the fireman would be unusual but perhaps not impossible, but there is no way that any tow truck operator would begin to mount a still-burning vehicle.
During the Victor Fuentes interrogation scene, Creasy sets his watch to 5:00, and an on-screen display of the time starts counting down. The time between the watch timer starting and the explosion is only 3:10, and even some of the on-screen countdown seconds are sped up.
When Creasy chases Aurelio Sanchez into his house, the weather is clear, but just as he opens the door for the first time with the small boy, it's raining outside. In the roof scene a few moments later, it's clear again.
The first day Creasy drops Pita off at school, he is told to come in. He is wearing a tan shirt and tie, but when he returns to the car he is wearing the black tee from the next day's ride that mom rode on.
When Creasy leaves the animal hospital and returns to the crime scene, a pre-2003 Lincoln Town Car carrying the reporter pulls out behind him. When they look in the rear view mirror it is a newer model of Town Car (2003+). At the crime scene it is back to being a pre-2003 model.
Right before the kidnapping scene, when Creasy is putting the dog in the car, the shot shows the dog entering the car. In the next shot from a different angle, the dog is still outside and enters the car again.
In the kidnapping scene the driver of the kidnapper's car reverses into the taxi at relatively high speed, which would have caused easily visible damage. When the kidnapper picks up Pita and the car is driving away the back end is clearly visible and is 100% intact.
When Jorge Gonzalez is removing the blue and red cover for his car, it clearly shows the windshield fully intact with no cracks. However, when he gets in the car, and Creasy gets in after him, the windshield is clearly cracked and broken in numerous places.
When Aurelio Sanchez attempts to escape in the red VW van, it crashes through a gate, trailing a large sheet over its roof. A moment later when it crashes into the truck, the sheet is over the windshield.
While Lupita's father is talking in the restaurant near the beginning of the movie, the flowers in front of him switch positions in the vase. Initially the flowers are facing to the left, toward the other man at the table. However, after Mr. Ramos mentions that he is letting his bodyguard go, the flowers are facing to the right, toward him.
When Creasy parks the Mercedes at Pita's school and Pita and Creasy get out of the car, the front wheels are pointed straight ahead. When Creasy returns to the car after signing Pita in, the front wheels are turned hard left.
At the middle of the movie, the camera takes an aerial shot of an orange building, with the captions telling you is the Mexican Police Headquarters. In reality, that building is a major hospital on the Interlomas zone.
Pita says that she is entering the 150 metres in 3 weeks but in the race she only does one turn and finishes back where she started. That is, 100 metres (150 metres is not a standard swimming distance whereas 100 metres is).
Captioning mistranslation. Fuentes tells Samuel that he has been authorized to participate "ex officio", and the caption translates this as "unofficially". However, "ex officio" means "by virtue of the office", in this case Fuentes' position in the Anti-Kidnapping Division.
The Kidnappers instruct Ramos to wait for a call in a public payphone in Avenida Reforma. Mexico City "Ladatel" card payphones can't receive calls. And, more specifically, the phone shown in the movie where the instructions are supposedly posted is the regular kind, which can't receive calls.
After Samuel Ramos shot himself with Creasy's bullet, the gun can be seen on the floor with the slide locked in the open position. That would only happen if an empty magazine was inserted into the gun, but Creasy had removed the magazine beforehand and Samuel loaded the bullet manually into the chamber. After firing the single bullet, the slide would close forward again.
Mariana tells Creasy that Fuentes is more heavily guarded than the president and travels by motorcade. It would stand to reason that, since he has money and influence, the car he travels in would be armored and with bullet resistant glass. Creasy doesn't shoot through the car at any time. It clearly shows bullets hitting the windshield, but not entering the vehicle. If they had, both occupants would have been killed. Creasy knows this and then tosses a fake grenade under the vehicle. This causes the driver to exit the car, and only then does Creasy shoot him.
After Creasy frees the young Mexican girl and walks out onto the dance floor shooting, the crowd doesn't panic, or begin any other rational action - they just keep dancing and working their way toward the door. And once they're outside they continue dancing (at a safe distance) outside the dance hall until and even after the dance hall explodes. No one is in fear; they just keep dancing and cheering.
It IS a rave party in Mexico, after all - intoxication, the mental confusion induced from the music and lights, and the close relations with guns in that society, would not create a state of alertness or danger.
No one (visibly) died, either - the patrons were corralled outside _before_ the explosions, so there was no sense of danger, and no emotional distress.
When Pita is writing down the license plate of a car following them, she states that she got all the numbers except for the last digit. Later, when Creasy browses through Pita's diary however, she has noted the complete number (C5T-K89), but the last digit had been erased afterwards.
When Creasy holds his Glock pistol to Gonzales' head and tells him to drive, the pistol's trigger is in the rearward position, meaning the firing mechanism is not cocked, and there is no round in the chamber. Chambering a round in a Glock pistol cocks the firing mechanism, which puts the trigger in the forward position. It can be assumed that a former special operator and assassin like Creasy would ensure his pistol is loaded and has a round in the chamber before using it.
After Creasy has fired the RPG into the Jeep in the motorcade and then first starts to drive off with Fuentes, the back-up lights of Fuentes's car are on, and then a moment later they are off once the car is out of the fire (this is probably because the car was filmed driving backwards into the fire, and then the film was run backwards to create the stunt).
Towards the end of the movie when the exchange is taking place, Creasy is wounded and kneeling down against the side rail of the bridge. He then stands up and looks back at Pita, then the scene goes back to him kneeling against the railing.
Towards the end of the scene where Creasey is cutting of Jorge Gonzales' fingers to help him remember stuff, Gonzales asks for a cigarette. Creasey puts one in his mouth but filter outwards. In the cut to the cigarette being lit, the cigarette is the right way round: filter in.
In the scene where Manzano is inspecting the vehicle that was sent off the cliff (with Jorge Gonzales in it) a film crew can be clearly seen filming at the bottom of the screen. One man is filming while the other is pushing a cart (from left to right) that a (reel to reel) camera and camera man are sitting on.