Factual error: 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).
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. In addition to the fact that you can't 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 also prevent 17-year olds from enlisting without consent by forging their parents' signatures.
Answer: It was a misconception about Jehovah's Witnesses beliefs. Only blood transfusions are discouraged in their beliefs, medically.