During his first tour when he is watching the mother and young boy with the grenade, they show the top and front view of an M1A2 tank but the side view is of a different tank without ballistic skirts.
During a handful of scenes Mustafa is shown handling and cleaning a Russian Dragunov SVD. However whenever Mustafa is shown in combat he uses a Romanian made PSL-54C.
At the dinner table, Kyle keys in on the father's scraped elbow. But his elbow is visible several times before this scene and it's not red/scraped.
When the SEALs go out on a mission after 'Biggles' is shot, they are attacked by a group of insurgents in a car; after killing the insurgents, one of the HMMWVs crash into the car and then into a wall, fracturing and holing the left front edge of the vehicle and taking a rear-view mirror off. In the same scene when the convoy parked at the target building, the same HMMWV appears undamaged.
After nursing the baby, Taya zips up her sweatshirt. The camera then switches to Chris holding the baby. When the camera switches back to Taya, her sweatshirt is unzipped again.
A SEAL would not be allowed to informally lead another unit's breaching operation, even if it was to "show them a thing or two to keep everyone [alive]". A breaching & room clearing operation is a finely tuned and intensively drilled routine, where each individual knows and performs his specific role relative to the group.
An outsider, even a SEAL, inserting themselves into the middle of such a delicate operation with no prior familiarization would jeopardize the safety of the entire team and would never be allowed.
When Kyle was watching the woman and child through his rifle scope, the camera shows him through the other end of the scope and his eye is magnified. In reality the opposite would happen, making his eye appear smaller.
During the military funeral, the American flag is handed off to the next of kin with the top of the triangle folded flag pointed towards the next of kin. This is incorrect. Proper military etiquette is to hand off the flag with the bottom edge of the folded flag towards the next of kin. Handing off the flag with the tip pointed towards the next of kin is called stabbing and is discouraged within the military honor guard community.
The movie strongly implies that Kyle was motivated to enlist by seeing images of Americans killed in terrorist attacks. However, in his memoir, Chris Kyle indicates that he had always intended to join the military after finishing school.
Chris Kyle is shown joining the SEALs after the 1998 US embassy bombings in Kenya and Tanzania, and subsequently gives his age as 30 years old during training. However, the end of the film shows his birth year as 1974, which would have made him around 24 during his training.
When Chris first Meets Taya in the bar scene, she first tells him her sister was married to a seal. She then says to Chris, "I'd never date a SEAL." Chris starts to walk away and she asks, "Where you going?" He says, "Well you said you'd never date a SEAL." She then says, "I said I'd never marry a SEAL." She never said I'd never marry a SEAL she just said her sister was married to a SEAL. However, Taya at first said that she'd never date a SEAL because she said that they're all full of themselves. Then, after Kyle explains to her that he's not full of himself because he'd lay down his life for his country, and Taya asks why, and Kyle told her that it was because it's the greatest country on earth and he'd do whatever he can to protect it, she liked that about him. So when Kyle started to walk away because she said that she'd never date a SEAL, Taya stopped him and changed her comment to she'd never marry a SEAL. Notice the smirk on her face when she changes her statement.
While on a night mission, Kyle and marines entered an Iraqi's home and were invited to stay for dinner. The lights were on in the kitchen. There was a large window with its curtains wide open exposing everyone to sniper fire. The curtains would have been closed upon entering the kitchen.
Kyle and Taya's babies are obviously prop dolls. Although the daughter doll's hand was CG-animated to move while Sienna Miller was holding it, Bradley Cooper can be seen subtly moving its arm with his thumb to make it seem like it is moving. The filmmakers acknowledged this after numerous reviews noted the fake baby, with screenwriter Jason Hall saying, "Real baby #1 showed up with a fever. Real baby #2 was [a] no show."
During some nighttime raids, just before entry into a lighted room, some of the actors had their night vision goggles (NVGs) set way too low on their face so that it was obvious they were looking "over" the actual tubes. In reality, you adjust the goggles so when you flip them down they sit right in front of your eyeballs.
Near the beginning of the film when the soldiers were being driven through a street in Iraq, the Arabic sign of a coffee shop is visible. A few seconds later, the same sign is seen again giving away the fact they they were going in rounds in a set made to mimic an Iraqi street.
When the Seal snipers are going on a mission to provide cover for Marines on patrol early in the movie, the first "Marine" out of the transport vehicle was wearing on his left shoulder the patch of the US Army 1st Cavalry Division, not a US Marine unit.
The haboob / dust storm is extremely realistic when seen in the distance and when the characters are enveloped in it. However, as it moves into the town and is near the helicopter, it stops and hangs there. If it had been real, it would have been moving at an extreme minimum of thirty miles an hour.
Chris Kyle enlisted in 1999, yet on his 2nd tour in Iraq (2004) someone in the movie calls him Chief. He didn't make Chief Petty Officer until just before he left the Navy in 2009, 5 years later.
Humvees throughout the movie are the original version. Late in 2006 General Dynamics started doing "Up Armour" retrofits in country to the vehicles adding heavier doors and bullet proof glass. Also there were snatch clevises added to the hinges which allowed the doors to be ripped off in emergencies. These should have been shown as the story evolved.
Near the beginning of the film (1999), Taya uses a type of cordless phone clearly labeled with the new lower case "at&t" logo that did not debut until 2005.
During the Iraqi war but after 2003, the US Army used the Bradley Fighting Vehicle (BFV) instead of the M113 armored personnel carrier that was shown in fight that took place in Al-Sadr city.
There is a college basketball game on in the bar after Kyle returns home after his final tour. It shows a game with Renaldo Balkman playing for South Carolina. Balkman graduated in 2006, Chris Kyle's final tour was in 2008.
When artillery explosions are going off in the distant background, we see the flash of the explosions and hear the sound at the same time. In fact at that distance, the sound of the explosions would be delayed by several seconds.
Kyle uses a Knight's Armament M110 suppressor, which inaccurately portrays muzzle flashes when fired, even clearly in daylight, which a suppressor by definition is supposed to eliminate. Secondly, a real suppressed shot sounds more like a hard, loud *slap* rather than the *pew* sound as portrayed in the film.
When Chris takes his infant daughter from Taya (after feeding) it is obvious that it is a doll and not a real infant. The baby is crying loudly but the action (or lack thereof) of the baby doesn't match.
When Kyle takes out the man who falls from a roof, the bang is heard before the whine of the bullet and its hit. Since Kyle use a high-velocity rifle, the bullet travels much faster than the sound of the rifle being fired. Hence, the bullet would whine by before the bang.
The drone that does a flyby has the engine sound from a Cessna 172.
Camera shadow visible when Chris meets his wife on the airfield after returning from Tour #1.
When Kyle is in the Texas tire shop with his son the door he opens has a sign stating "This repair facility is registered with the state department of consumer affairs" and has the seal of the State of California on it.
A trained military man would never point a weapon at another person, whether the weapon is "presumed unloaded" or not, unless he intended to use it. This rule is more fundamental than the rule about never leaving your weapon on the ground.
When Kyle dials his scope up to make his final shot, the cross hairs move up. In reality using the nightforce scope, the crosshairs should have moved down making Kyle reposition the rifle to align the bore and the crosshairs for the longer shot distance. IE crosshairs move down, you must re-aim to hit your target. In reality, the shooter cannot see any movement of the crosshairs as the view is fixed.
When Kyle is in the bar after his final tour. The flag over the bar is displayed incorrectly. The canton is supposed to be to the left as you look at it. The flag over the bar is displayed backwards. And is not proper flag etiquette.