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. Wong 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.
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.
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.