Character mistake: When Ruzek and Voight are questioning Wade Henslow (the father of missing girl) at the station, after finding out he lied and set up his own security to find his daughter Adam looks at Wade Henson but addresses him as "Mr. Larson" which is actually the last name of one of the kidnappers they found DOA who got into the gun fight with his security guy, the ex-cop Kenny. (00:21:26)
Character mistake: Before Kevin Atwater and Doyle fight they both put their badges and guns down on a barrel. After Atwater beats up Doyle, he retrieves Doyle's gun and holds it to Doyle's head and drops it to the ground. Atwater walks away, but he never retrieved his own badge and gun before walking away. The gun and badge are on the barrel, and he does not return to retrieve them. (00:58:37 - 00:59:32)
Character mistake: Alvin Olinsky appears in this episode investigating the bombings in which Trudy was involved, but he died at the end of season 5.
Suggested correction: Where do you see Alvin (or even the actor Elias Koteas) in the scene? I couldn't see him in this episode.