Revealing mistake: When Amanda and Fin are in Atlanta following up on their rape case they walk past several cars with visible Georgia license plates mounted on the front. Georgia is a rear plate-only state, and wouldn't have had plates mounted on the front of the cars as shown here.
Character mistake: The fetus' blood type was AB and the mother had a known type of A. So Dr. Huang said the Father had to be type B which is not completely true. The father could also be type AB as long as he had a single chromosomal copy of the B allele, which any doctor would know. During meiosis only half your genetic DNA is passed on to the offspring.
Revealing mistake: In the scene where Detective Munch visits the hospital room of a young comatose girl for the first time, we see that the girl's left arm is alongside her body above the top sheet. As Munch approaches the bed, we now see that her arm is below the top sheet. When Munch visits the still-comatose girl a second time in the last scene of the episode, we can see in the foreground as he is entering the room that the girl's head is turned, facing her right. As he pauses to watch her, we then see in the next shot that she is now facing upright towards the ceiling. In this same shot, you will also notice the purportedly still-comatose girl slightly move her head and lips as if swallowing.
Visible crew/equipment: After most of Susie's severed remains are found at the beach, it cuts to ADA Barba walking into the conference room as he says, "Twelve hours after Rudnick posts bail, a potential prosecution witness is found in pieces with the morning tide," and under the table we can see two reddish long tape marks on the floor, where Olivia stands during the scene.
Continuity mistake: Fin is talking to the suspect in the interrogation room. After he calls Fin a racist remark the camera goes to outside the room where Cabot and Cragen are watching in on them from the 2 way window. It then goes back to Fin with the suspect inside the room. When the camera points at the suspect you can see blinds are actually shut on the 2 way window behind him. So Cabot and Cragen could not possibly see in like they were supposed to.
Plot hole: Although William Lewis burns his fingertips in an attempt to avoid identification, the Special Victims Unit could have identified him early on by examining the remaining unburned area of Lewis' hands, and in good police procedure still record the newly scarred fingerprints, as these new scars actually make his fingerprints more unique. His scarred fingerprints would still be at Alice's apartment crime scene, and during the trial at the end of the episode the prosecution would still have a strong argument for placing Lewis at Alice's apartment, even if the DNA evidence is thrown out because of alleged cross contamination.
Factual error: When Stabler's son Dickie is trying to join the Army, Dickie's recruiter tells Stabler that he can join at 16 with parental consent. This is incorrect, you have to be at least 17 to join the U.S. Army even with parental consent. Even if you could join at 16, the consent papers that Dickie bought to Stabler at the end of the episode can't be signed without a recruiter or notary public present and signing the papers at the same time. This is to prevent cases where a parent who had a change of heart can claim they didn't sign and to prevent 17-year olds from enlisting without consent by forging their parents' signatures.
Character mistake: In the scene where Detective Benson is presenting possible home care suspects for the rape of Cara, she says that Drew Cummings is on trial for distribution of Schedule 4 drugs. When asked which ones by Detective Stabler, she says "Vicodin, Percocet, Oxycontin, you name it..." Vicodin was a Schedule 3 drug, recently rescheduled to Schedule 2. Percocet and Oxycontin, the main ingredient for both being oxycodone, have always been Schedule 2. Schedule 4 drugs are drugs like Xanax and Phentermine, less addictive with lower legal penalties for distribution.
Character mistake: When Casey is talking to Rebecca Balthus about Jennifer's defense, Balthus claims that Jennifer is innocent and intends to prove it. While she can present a defense, Balthus is not required to prove anything: the burden of proof lies solely on Casey; Jennifer possesses what is called the presumption of innocence, the basic principle that she is considered innocent until it's proven she's guilty.
Character mistake: When Munch and Finn visit victim's apartment, Munch states that the glass in the broken window is tempered, The glass is not tempered but more likely laminated wire glass; due to he fact that the glass is still intact and the child had to use wire cutters to get out.
Continuity mistake: When Stabler steps out to confront Tarzi, there is a long, brown brick wall to Tarzi's right. Tarzi then turns and runs across the street and is followed by Fin. Munch steps out and yells "halt!" There is another shot of Tarzi and he stops again. Right before he is tackled by Fin, behind him, to his right, is the same brick wall as before even though he crossed the street and ran down the block.
Factual error: When sergeant Benson is in the bathroom alone after it has been declared clear she looks at her phone to see a picture message from Lewis of the little girl he has tied up. She then texts him back saying "where are you" but at the top of the screen it says unknown as if the sender has blocked their number, so it would be physically impossible for sergeant Benson to reply to this message.
Factual error: The episode took a lot of liberties to further the plot when Amelia Albers was arrested by the Coast Guard in ADA Barba's office. While the story mentioned a real controversial military pamphlet on how victims should respond to a sexual assault, at the time the episode took place the military was under a massive investigation over sexual assaults by Washington, was being publicly criticized for a lack of assault victim support, and had a bill going through Congress to make it easier for victims to report their attackers. There is no way any military prosecutor would have been given clearance to charge Amelia with adultery or fraternization while the men she was accused of sleeping with were charged with gang-raping her. Doing so would bring a lot of unwanted bad press as well as a congressional investigation on the Coast Guard that would almost certainly want to know why they are attempting to cover up a rape by charging the victim instead, especially when the rape victim was an admiral's daughter.
Character mistake: At the end of the episode, Abby Carmichael says that professor Rousseau will be convicted of three class-A felonies, with a term of a year each. According to NY state laws, three class-A felonies would lead to the death penalty; Abby meant to say three class-A misdemeanors.
Deliberate mistake: When James is shot on the courthouse steps, the crowd of reporters that has gathered quickly scatters to escape the gunfire. One of them is a woman in a black windbreaker holding a camera. The camera cuts away briefly and then back to the crowd - you see the exact same people, including the woman in black running in the exact opposite direction as before. The footage was apparently mirrored and repeated for the second shot of the fleeing crowd.
Factual error: Season 9 episode 18 (TRADE): The scene where Pierson Bartlett is on the stand, he pulls a spoon out of his jacket. This would never be allowed. He wouldn't get through the metal detector with any metal that could be used as a weapon. He would either have to take it back to his car, or leave it at the security desk.
Factual error: Season 11, episode 2 ("Sugar"). When tracing the "Master Baiter" the detective says she can't trace the subject because "the HTML code is scrambled". There is no such thing as scrambled HTML, and on top of that HTML can never give away any information about a subject's location. Also, she can't get his IP address because it constantly changes. Yet, she does know from what exact wifi-spot he connected. If you get random IP-addresses, for instance by using random proxy servers, you can't pinpoint a location (which was of course why he used this technique).
Continuity mistake: Season 11, Episode 3 "Solitary": When Donovan pushes Stabler off the roof, Stabler is standing with his back facing the parapet and goes straight over. However, when he's shown on the roof below after he's landed, he's turned almost a full 90 degrees and is lying parallel to the building.
Continuity mistake: When Benson and Stabler are interviewing Virginia at the end of the episode, when she admits to committing the crime, she breaks down into tears and her face turns red. The next shot is from over her shoulder, and her expression is normal. In the very next shot, from the front, her face is flushed and tears again.
Factual error: The way that the drug Scopolamine is described is not accurate. It does not render the victim "unable to resist instructions". It can produce "twilight sleep", delirium and euphoria, but does not give anyone complete control over another person as depicted in the episode.