When the diver announces what he has found to the agent by the river, he says that the Crown Vic had government plates. However, we know from the car wash scene that the Crown Vic had Pennsylvania plates.
When Fenn fires the senator's sidearm on the mountaintop, only 4 rounds are fired before the gun clicks empty and the slides goes back, meaning that either the senator had been busy with his gun earlier or he's in the habit of carrying around a barely loaded weapon.
In the beginning when the guys who set up Swagger are discussing him, they refer to him as the best US Army sniper, and his fatigues in the opening scene are in fact Army. But in the rest of the film he is said to be a Marine and referred to as Gunnery Sergeant, a Marine-only rank.
When Swagger backs the car into the river, the trunk is open and you can see that there is no upholstery and it is empty. While in the car wash we see there are miscellaneous items and upholstery in the trunk.
At the start of the film when both snipers are first seen watching the road, a close shot shows Bob Lee's rifle bolt open, another shot shows it closed. When the order comes through to fire, Bob then loads the rifle.
When Memphis is in the computer room checking the VIN that Sarah gave him, he picks up the photo and begins to type in a string of numbers on the number pad. When the shot changes to the computer monitor the VIN being entered has no numbers it only shows LFMY. However the complete VIN of LFMYU70E4YUA65879 is already displayed in a grayed out window to the left.
In the scene where Swagger advises Payne not to call his dog, you can see that there is no license plate on the front of the vehicle, however when Swagger comes out and takes a photo with his cell phone, it is magically there.
In the scene where Sarah fixes Swagger's bandage at the kitchen table, in the first several frames her front hair is held back by a clip, but suddenly the clip disappears and her hair is simply back behind her ears in the rest of the scene.
The first shot Swagger makes, kills an enemy standing in the back of a truck. The man falls into the back of the truck. In the next shot, when the truck falls over, the dead man in the back suddenly disappeared.
In the glacier scene, when Sara takes her revenge on the henchman who broke into her house, she fires four rounds... wouldn't mean much if the weapon was only partially loaded, but in the close-up showing her emotional release immediately thereafter, the bolt is shown locked back which indicates an empty magazine. The scene *after* that close-up briefly shows the bolt in the normal position as though there are still rounds in the magazine.
During the shooting scene at Michael Sandor's place, when the first agent breaks the door open and is eventually shot dead by Swagger, you can clearly see that outside it's raining heavily, while it's perfectly sunny throughout the rest of the scene.
In the car wash scene, Swagger is applying Quikclot to two wounds, one in the shoulder/pectoral area and one in the abdomen. Later, Fenn is cleaning the shoulder/pectoral wound, but there is no abdomen wound.
When Johnson leaves the meeting with Swagger and the Attorney General, he is seen standing by the final chair of the table. After the AG is shown pictures by Memphis, the AG looks to Johnson and he is standing about half way down the table, not the end near Swagger.
During the mountaintop scene, the position and brightness of the sun varies from scene to scene. For example, when Wahlburg surrenders and kneels in the snow the sun is at his back. In the following shot he is facing the sun.
During the mountaintop scene, and after shooting the last enemy sniper, Swagger pulls the hood of his winter ghillie suit off before focusing on his shot at Payne. After taking the shot and then shooting Payne a second time, we see Swagger from a distance standing on the mountaintop where he removes the hood of the ghillie suit again.
When Swagger is being chased by the cops, all of the cars chasing him have both front and rear plates to identify them. However when he goes down a hill and two cop cars are following him, the second car has a plate with a number on the front, the first car has a blank plate. The car would have a number on the front to identify the car, not just a blank plate.
During the scene in which Wahlberg backs the car into the river, you can see a metal bar attached to the back bumper which was used to brace the impact of the car hitting the water, and to level out the car so it would sink evenly.
While Swagger is in Baltimore he walks down the steps of Federal Hill. He enters a taxi cab on Battery Avenue that drives towards the Inner Harbor. Battery Avenue is a "one-way" street that goes in the opposite direction (away from the harbor).
When Swagger is being chased by police in the stolen FBI vehicle he makes a right off Front St. onto Girard Avenue heading south. When he glances in his rear view mirror, a McDonalds can be seen through the windshield in front of him. That McDonalds would only have been visible if he made a left onto Girard heading north.
Before swagger is hit by a tractor trailer in the stolen FBI vehicle, he is seen speeding downhill towards the river. There are no such downhill roads leading to Delaware River in Philadelphia. The layout of land along the Delaware River is very flat.
Towards the end of the movie it shows Memphis and Swagger standing on a bridge that is supposedly located outside of Bozeman, MT. (1) The terrain is not even close to that of the city of Bozeman (2) There are three interstate overpasses in the city of Bozeman, and again, the terrain does not match any of the corresponding overpasses.
In the roadblock news clip which was supposed to be the Wind River Mountain area of Wyoming, the cars behind the roadblock have no front plates. While it is possible these could be all out of state vehicles, All Wyoming vehicles have both front and back license plates.
In the first car chase when Swagger is trying to escape from the set-up, when he is cornered by multiple police cars (just before he backs his car into the river), you can hear the police dispatcher call out over the scanner, "Suspect vehicle collided with a truck under the 95. He's at Market and Columbus." A Philadelphian would not refer to I-95 as "the" 95, but simply "95". The use of "the" to refer to a highway/freeway (e.g. "the 10", "the 405") is unique to Southern California.
When the Crown Vic is backed into the river, various camera angles show a very flat topography which is consistent with Philadelphia. After the car is in the river, the first shot back toward the bridge clearly shows tall mountains in the background. No such mountains exist near Philadelphia.
At the beginning of the movie when the helicopter comes he switches to a Barrett M82 which is a semi-auto rifle but he is seen cycling the rifle by hand because the blanks being shot for filming did not produce enough pressure to work the action.
When Swagger tests his rifle on the can of stew, the bullet is show striking the can from the bottom of the screen. But at such a long distance, the shot is more like a lob: the bullet would have passed (unseen) "up" the field of view and then dropped back down onto the target.
At the mountaintop exchange scene, not one of the actors seems to be effected by the considerable down-force caused by the still spinning rotor blades of the helicopter as they get out of it. Even Fenn's shoulder-length hair moves only slightly and the snow beneath their feet seems completely unperturbed by the wind caused by the helicopter. A helicopter touching down in a snowy location would cause a small blizzard and anyone getting out would at the very least be hunkered down and making some attempt to cover themselves from the wind and snow, rather than casually strolling along.
As Colonel Johnson leaves the Department of Justice conference room near the end of the movie, there is a US flag and a Washington, DC city flag (white with 3 red stars and 2 red stripes - based on the coat of arms of George Washington's family) in the hall. A Federal office building would not display the Washington, DC flag, only the American flag (and perhaps a Department of Justice flag).
When the archbishop is shot, the sound of the rifle shot is heard at the same time as the bullet strikes. Depending on the speed of the bullet, it would take at least several seconds for the sound to reach the target.
When the Spotter (Donnie Fenn) gives his Sniper (Bob Lee Swagger) range info to their first target, he says "870 yards and closing" when in fact the target is moving AWAY from their position. Swagger shoots both the gunner in the back of the truck and the driver from behind. Subsequent targets approach in a "closing" direction of travel.
In the opening scene, Donnie calls out the distance to 'hostile forces' as 870 m, engages the helicopter with an M4, and then returns fire on the 'hostile forces' at 870 m. Giving the strong impression that his M203 grenade launcher is effective to 870 m when, in reality, its maximum range is closer to 400 m and its effective range is closer to 150 m.
When Swagger makes the supposed intravenous needle stick, he pushes the needle straight down into the antecubetal fossa after using a tourniquet to occlude a vein to get distention for the venipuncture. The puncture is properly made parallel to the skin surface, not deeply perpendicular as was shown.
Inexplicably, the three men who plan to kill Memphis and make it look like a suicide beat him bruised and bloody beforehand. These wounds would surely raise unwanted questions about the circumstances of his death.
During the ranch scene just after the flashback to the helicopter gun-run, if you look carefully enough, you can see on Swagger's M4 Carbine, that the selector switch is on Semi-Automatic. But throughout the shootout, he fires on full-auto or in bursts.
Swagger is referred to throughout the movie as a Marine, or 'Gunnery Sergeant'. However, when in Ethiopia, he is wearing Army digital fatigues. His spotter is also wearing Army Digital, and military sniping units only work together with someone of the same branch.
When Nick Memphis is scanning through documents about Swagger, there is an article about Wimbledon Cup Winners. The photo shows Swagger and the caption reads "Winner of the Wimbledon Cup" Sgt. Major Bob Lee Swagger. This is incorrect as Swagger is a Gunnery Sergeant, not a Sergeant Major.
When the crippled sniper shoots himself under the chin, no bullet is actually fired from the gun. If you watch the scene frame-by-frame, a jet of air comes out of the gun and the actor's head cocks back. His neck is intact.
The goof items below may give away important plot points.
When Swagger is shot and uses Quickclot on himself. You DO NOT open Quickclot with your mouth - if even a small amount of it gets in your mouth it will cause a very large amount of pain and a massive case of cotton mouth. Also, you do not use it on anything other than arms or legs, putting it on your stomach or upper chest could cause even worse problems if it were to get anywhere near your lungs or stomach.
When Swagger takes care of the senator and his cronies in the lodge at the end of the movie, he breaks open a gas valve. A few moments later, the gas explodes, destroying the entire house. The gas did not have enough time to fill the house. Even worse, such an explosion would only happen if the gas were allowed to saturate the entire structure. Yet, several windows were shot out, a score of bullet holes were shot into the floor and one of the senator's bodyguards fell through the ceiling and into the den, giving the gas plenty of avenues to escape.