Continuity mistake: 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: 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. (00:25:00)
Answer: It was a misconception about Jehovah's Witnesses beliefs. Only blood transfusions are discouraged in their beliefs, medically.