The cityscape flyover shown just before John starts his security job is Calgary, Canada, not any city in South Carolina. The two brown towers in the center are the Petro Canada head office. The hexagonal one in the front is the Telus head office, on which the logo can be seen.
After John Triton is discharged, he flies back to his hometown in an IranAir Boeing 747SP. The Homa tail logo is clearly visible. The archive footage used in this scene must be at least 20 years old because the plane wears the old IranAir livery (navy/dark blue stripe on the windows/fuselage, silver belly) and not the new all white fuselage paint. Also the old British Airways liveries are visible in the background. The footage is most likely to be of Runway 27R at Heathrow Airport Intl. London, U.K.
When Triton bursts in the terrorists' hideout, he wildly sprays a room full of hostages with fully automatic fire, while "aiming" from the hip. Not even the most incompetent Marine would ever do this, much less a Force Recon Marine.
Force Reconnaissance Marines are required to be both military SCUBA and military parachute qualified. John Triton does not have parachute qualification wings, or the gold diver's badge on his dress blues, or his utility uniform.
The police Camaro is marked as having an ABS (Anti-lock Braking System) system. This system would have prevented John from locking up the wheels of the vehicle, showing that either the vehicle has been tampered with or is a different vehicle when the wheels are locked up.
John Triton is seen early in the movie driving a police Camaro SS, the windshield of which he removed with a nightstick. In subsequent shots, however, even as he drives at a high rate of speed neither his clothes nor items in the car show any indication of wind inside the vehicle.
When John is giving chase in the police car, the roof of the vehicle is removed due to construction equipment. Soon thereafter, John is shown staring in the rear-view mirror, which would no longer be there. In actuality, it should never have been there, considering he removed the windshield at the gas station.
After Triton comes up to the spot where the crooks hide from the helicopter, he looks down at footprints. They are perfectly formed with no leaves around them even though the surrounding ground is covered with them.
After fighting the two hillbillies in the barn, Cena immediately runs out the door after his wife. A few seconds later he's again holding the gigantic knife, though he never stopped to pick it up. It is obvious the fight scene was added later in filming, possibly to pad the time.
When Triton exits the burning gas station, he is dry, then he is shown running alongside the cop car as the fire continues to explode and burn behind him and he is covered in fireproof gel, then when he reaches the downed officer he is dry again.
All throughout the movie, Triton takes many hard, brutal punches to the face but there's never any signs of damage. Even during the initial kidnapping, he was running full speed when one of the jewel thieves hit him in his forehead with fire extinguisher, knocking him unconscious. Finally, in the closing minutes of the film, Triton is hit in the ribs with a sledgehammer but it apparently didn't do anything as he proves to be perfectly fine minutes later, again.
When Triton is first taking the Police Camaro, he informs the people on the radio that the bad guys are traveling on I-95. I-95 does run through South Carolina, but it is a 4-lane divided controlled-access highway. The bad guys are traveling on a 2-lane undivided highway.
A round from the M203 that Triton also uses in the opening sequence must travel around 15 meters before it will arm and detonate; should it stop at a shorter distance such as the inside of a room, it will bounce off whatever it hits without exploding.
The helicopter firing on the Taliban is not a U.S. or Allied aircraft. The aircraft is a dual seat medium lift helicopter with outriggers. The U.S. and her allies do not have medium lift helicopters that support outriggers. The largest U.S. helicopter that supports weapons on an outrigger is the UH-60 Blackhawk
During the shooting scene in the house near the swamp, Rome shoots at Triton at least ten times, then after he leaves the house, he fires at least fifteen more shots without reloading, which is impossible for that pistol.
The M16A2 as used by Triton in the opening sequence has a trigger set of S-1-3, that is, it is capable of firing a maximum of 3 rounds for each trigger pull, yet Triton sprays the room of terrorists at full auto.
When Robert Patrick's character is firing at the police car outside of the gas station, a slo-mo CGI shot shows shell casings flipping through the air. One close-up reads ".45mm" on the casing. No such caliber bullet exists, and would be ridiculously small and useless if it did. This is obviously a mistake made by confusing .45 caliber and 9mm handguns.
Duting the fight in the burning fuel shed between Rome and Triton, Rome attacks Triton with a chainsaw. Triton uses a monkey wrench handle to block the moving blade chain of the saw. In a real situation like that, the chain from the saw would have either snapped and unwound from the saw like a bladed whip, or it would have shattered and sent shrapnel into both Triton and Rome.
In the scene where they have started the generator to switch on the electricity they take some beer bottles out of the fridge which have condensation on them, showing they are chilled yet they have only just switched the fridge on.
In the scene where the B4C police Camaro is shot in the doors and fenders, it is shown to have bullet holes similar to normal sheet metal, when in reality all Camaros from 1993-2002 had polymer fenders and fiberglass doors.
Before and after the semi crashes into the water, Kate exerts a lot of energy while trying to free herself. Then once truck is completely submerged, they show her constantly letting out air while still trying to free herself. It takes Triton a little over two minutes to finish his fight then remove her from the water.
Most police agencies including the South Carolina police do not use wheel guns. All revolvers have been replaced by semi-auto pistol usually in a 9mm size. However, many agencies do permit individual officers to use weapons of their own choice, so it is possible, although not likely, for a revolver to be used by a law officer.
Immediately after being kidnapped by the gang, Kate's identity is discovered by an active dependent military Id in the vehicle. First: When John Triton was discharged, she would have lost her military ID as a matter of procedure. Second, the ID states that she is "Mrs. Triton, Kate." and "Sgt. Triton, John." The military ID does not show information in this manner.
When the police car is blown into the air by an anti-tank rocket at the end of the robbery, the explosion (with all its excess of gasoline flames) originates below the center of the vehicle, someplace it would be impossible for the rocket to reach.