Character mistake: A radio report refers to a character with two different police ranks with 15 seconds apart in the same broadcast - first as a Police Chief and a few seconds later as a Captain. (00:21:28)
Character mistake: Zeke makes the bold claim that "John Kramer didn't target cops." This is completely and utterly false, and a cop like him should know better. Kramer repeatedly targeted cops. In fact, both "Saw II" and "Saw IV" have officers (Detective Mathews and SWAT Commander Rigg) as Kramer's main target.
Character mistake: Bart is sitting on a bench outside the hotel. After Detective Espada talks to the Mercer hotel manager/owner, he goes to talk to Bart. Bart has blood on both hands and lower left sleeve. Detective Espada is supposed to be investigating a fresh murder case that puts Bart at the scene, but he does not confiscate Bart's bloody clothes, conduct a gun powder test on Bart's hands to check for residue, or take him to the police station for formal questioning. Espada did not follow police protocol. (00:17:36)