After Officer Taylor finds money and guns in a truck, he shows us his paperwork which is dated 8/19/2012. However, the police cameras always show us dates in 2011.
When Brian and Janet sing "Hey Ma," they are both wearing wedding rings. At that time in the movie, they weren't married yet; Brian hasn't even mentioned the idea of marriage to his partner Mike yet.
When Taylor and Zavala are patrolling the town at night and having a conversation, the passenger door seems to keep locking and unlocking after every cut to Taylor.
When they are driving and spot the fire they help with the dispatcher asks for a location which they identify at 1002 6th St. During the scene following at the house that they find the human trafficking ring, they ask for backup which the dispatcher calls for additional vehicles to respond to 1002 6th St. A minute earlier, they had identified this house as "9318 53 Street."
On Taylor's uniform, he has a small USMC Eagle, Globe, Anchor pin on the corner of his left breast pocket. Throughout the movie, including connected scenes, it disappears and reappears.
During the locker room scene, Officer Taylor states the standard issue sidearm for the LAPD is a Glock 19. This is incorrect, as the standard issue sidearm is a Glock 17 (9mm) issued to recruits in the police academy which they must carry for their one (1) year probationary period. After successfully completing their probation period, officers can then purchase and carry a firearm of their choice off the department's "Approved for Carry" list, which includes the Glock 19.
When Officers Brian Taylor and Mike Zavala are on night patrol, both characters are wearing white under their Class A uniforms. Night patrol officers wear black under their uniforms.
In the locker room scene Officer Taylor shows his "Spyderco" tactical knife. This is incorrect: the knife he shows is the Smith and Wesson First Responder knife.
In the locker room scene at the beginning of the film, when Taylor shows off his department issued Glock 19, the markings indicate that it is actually a Glock 22.
During the pursuit in the opening of the film, the officers pass by a homeless man on the ground as well as a yellow truck on its side with a potentially hurt passenger trying to exit the vehicle. Police procedure requires an officer to stop and render aid, even in a pursuit. It does not appear any other police unit was following the officers (a second unit could have stopped to render aid), so they would have been required to end the pursuit and help the injured.
When showing the burned up stolen vehicle the officer states they found two types of shell casings, 9mm and 45. However, the brass they find is 7.62x39mm, 9mm, and .45 ACP, correlating to the three calibers of weapons used in the drive by scene.
The Mexican gang fires several automatic weapons to the rival gang members from a short distance in a straight direction and yet no one is hurt apart from one character who dies in the shooting. It is very unlikely that anyone else was injured or dead.
In the final shootout, the Curbside gang members see police vehicles approach on all sides of the alley, blocking their escape. However, when the shootout occurs seconds later there is no longer any police cars behind them for some reason. If there had been, the police would have had to worry about crossfire and injuring fellow officers.
At 1:11'00", Mike is filming himself and talks directly to the camera but it is not the same angle as when the camera is seen from a wider view.
When the main characters pull over the guy with the chili and the golden AK47 - the time stamp on the dashboard cam reads 6/8/2011. In the next scene, when Officer Taylor holds up the Receipt For Property Taken into Custody form - the "lifeblood" of the organization - it has a date of 8-19-12. Man, these guys really do hate paperwork! That's 438 days that Mr. Chili had to wait forever for his arraignment.
When Taylor and Zavala pull over the Mexican cowboy with the money hidden in beans and the gold AK47, Taylor radios out right before the traffic stop which reveals the time on his watch says 8:16. Considering he is law enforcement and ex-military, we can assume the watch is in military time, which makes it 8:16 am. However, the dash cam shows the time as 17:39, or 5:39 pm.
Throughout the entire movie while "Brian" and "Mike" are inside their patrol vehicle, where the center "cage" or "divider" mounts to the vehicle above each person's seat belt, the plastic cap that normally covers the mounting bolt is sometimes there and other times it's not. The bolt is gold in color and it seems to happen to "Brian's" side more often. Sometimes the gray cap is there covering the tops of the seat belts, other times the gold bolt is visible.
When the two officers are performing the "Welfare Check" on the house, right as they are about to kick in the door the reflection of the window to the left of them shows a blue tent and several crew members in the back behind the scene.
When Van Hauser and Sook come to release Taylor and Zavala to go back on patrol, after he goes under the tape he takes his cigar out of his mouth he spits. This is an official crime scene, that's whats called "leaving your own evidence on the crime scene." Professional police officers don't spit or leave any of their bodily functions on the crime scene. That confuses the case. They would also not allow an officer on duty to smoke s cigar let alone inside a crime scene.
While chasing the minivan, Brian says that the car they're chasing is a Toyota minivan but it's really a Ford Freestar.
A policeman cuts off duct tape holding a child's wrists by flicking the knife towards the child's face. This is very dangerous.
The firemen do not fit the two coughing and struggling policemen with oxygen masks.
At no time when using their radios do the characters use the phonetic alphabet. This is a standard is almost all Emergency Services.