Johnny C takes his vest off, but it is back on again later momentarily.
The hand pierced by the spike heals instantly.
When Kruger and DeGuerin are divided between the glass wall, DeGuerin speaks to Kruger through the wall and can be heard easily, but Kruger's loud yell afterward was almost undetectable on the other side.
When Kruger opens the door in the plane he switches from holding on to something (to avoid getting sucked out of the plane) and holding the gun with both hands, between shots. (And if it was so important to hold onto something, wouldn't he have been sucked out of the plane when he was holding the gun with both hands?)
The fake blood that John Kruger is putting on Johnny C.'s shirt at the beginning of the film goes instantly from a line of drizzled red dye to a solid stain.
DeGuerin's agents say they traced the 'run' call from Kruger to Lee to an apartment in Chinatown. It is impossible to determine the location a pager receives a call, much less the specific apartment.
Cyrez's high-security vault would surely use a deadbolt lock. In that case, shooting up the code-entry keypad would not unlock it, but would make it impossible to unlock.
Between the time Kruger and Lee enter the red van and the van explodes is less than 10 seconds. It would be impossible for both of them to leave their seats and drop into the hole under the van in that length of time.
The technician on the 727 is able to trace John Kruger's call from his cellphone to an apartment in NYC. However, Kruger had not called the apartment; rather, he called a pager. There would be no way to trace the call anywhere other than to the paging company's office.
The nurse responds to Johnny C's "flat-line" asystole rhythm by saying "he's fibrillating." Medical personnel do not shock without checking for a pulse. Nor would they shock someone moving or speaking. This is obviously a clear shot at some medical personnel lacking training or just inserted as a gag for the viewer.
When trapped by the glass door in the weapons building, Kruger stops firing because the bullets are ineffective, not because he has run out. Therefore, a later shot at the sprinkler system without reloading is reasonable.
When the rail guns are fired there is little recoil yet Newton's law states that "for every action there is an equal and opposite reaction". If the rail gun slugs were as powerful as depicted the guns would be almost impossible to hold on to because of the massive recoil. Newton's law doesn't apply if the gun is designed absorb the recoil instead of the person holding the gun.
Near the end of the movie, Lee and Kruger are looking at the offshore bank accounts. Lee says pointing at the screen, "UBS, that's Union Bank Swiss." Kruger brings up information about the "UBS" account, except that instead of "UBS" the computer screen now reads "USB" and stays that way through the rest of the scene.
The type of parachute in the parachute scene is seen as round which has no controls, yet Kruger, when seen in close-up, has controls and is able to turn the parachute to face the plane.
John gets a nail stuck in his hand, and then pulls it out, but in the very next scene he is holding a gun with that same hand. If someone had such a thick nail in his hand it would have damaged the median, and radial nerves in the hand and he would not be able to grasp or release any object.
When Donahue shoots himself, the glass behind him shatters before his head recoils.
When Kruger is hurtling toward the junkyard car, the windows blow out before impact.
In the reptile house Kruger says he has two rounds left. He uses those to shoot the glass out to free the crocodiles and then to shoot the attacking croc. His Desert Eagle should have locked back after the final round is expended, but it did not.
Kruger set the zoo as the meeting place if she had to flee the apartment. There was no back up plan for if something happened when the zoo was closed.
The logo on the lab coat of computer tech that traces the terminal Kruger is using after they sneak into the Cyrez building has the incorrect "Cyrex" name. (See also Trivia section.)
When Kruger is programming the credit card in the safe-house, he swipes it through the machine with the magnetic strip at the top of the card instead of the bottom.
John Kruger uses a standard compact film camera to take pictures of Johnny C. and his wife at their home to prove that they are dead 4:39. But the photos he took of Johnny C. and his wife that he pulls out of his pocket 5:37 are photos produced by a Polaroid Instant Film type camera.
When the dart Kruger pulls out of his belt to throw at DeGuerin is airborne, you can see wires, as well as the trajectory being off from where Krugers hand in and how he threw it. Also, when it hits DeGuerin's arm, it doesn't lodge into his arm - you can actually see it deflect via the wires.
When DeGuerin and his team of agents jump out of helicopters at the end of the movie, the sound of shotguns 'cocking' is heard even though all the agents are holding assault rifles.
After he's been shot at buy the railguns in the warehouse, John is digging himself out. On the left, there is very clearly a gloved hand holding a welder up to a metal surface to create sparking effects.
Lee and Kruger rush from Lee's house just as it explodes, however Lee remembers to grab her purse. In a later scene Kruger burns Lee's ID and Credit Cards. Lee also is in possession of the duplicate disc.
When Johnny and John walk towards the car after getting out of the ambulance, a reflection of the boom mike can be clearly seen.
Lee claims that she doesn't know what is on the encrypted disc. But she obviously does know as she was there when she herself copied it and saw the 3D schematic of the rail gun on the screen.
After Lee and Kruger escape from the zoo, DeGuerin tells Belly that he lost three troopers. However, Kruger releases the crocodiles to eat DeGuerin's three troopers. Kruger himself, when he breaks into the crocodile room, shoots one of DeGuerin's troopers. So, DeGuerin should say that Kruger killed four of his troopers.
When Lee Cullen is wired and wearing the camera on the elevator, she tells the FBI agents (via the microphone) which floor William Donohue's office is on, Then the security guard angrily tells her, "I know where it is". All she had to do was face the button panel which would have shown on her hidden camera. The FBI agents in the van would see which button is lit.
In the opening credits sequence as John Kruger is seen gearing and preparing to rescue Johnny Castelelone from the mob hit-men, a photo of Lee Cullen is seen being burned. John Kruger hasn't met Lee Cullen yet and doesn't get assigned to protect her until after he has rescued Johnny Castelelone and it's unclear how he is in possession of her photo.