Visible crew/equipment: When Gibbs and Ziva are in the "safehouse" Ziva set up for Ari, a crew member and his boom microphone are seen on the left of the screen, right before Gibbs climbs the ladder to remove the hidden camera spying on them. (00:30:10)
Factual error: When McGee is tracing the who sent the request for the polygraphs, the map bounces around the world. When he says Kurdistan, the map shows Armenia, and when it hits the Dominican Republic, McGee says Puerto Rico. (00:26:50)
Continuity mistake: In the Episode "Sharif Returns" When Ducky shows Gibbs the eye in the gladd vial, it alternates between being completely submerged in the fluid to sticking out the top.
Continuity mistake: When Gibbs and the team meet the sheriff and ask to be shown the crime scene, he states that it was in the Edenvale motel room 8. In the opening scene the door that the gentleman knocked on and subsequently got his feet covered in blood from the body bleeding out was room 1. (00:00:50 - 00:04:05)
Visible crew/equipment: At the start of the sexual harassment class, when Tracy Taylor explains, "A coworker shows you a cartoon or photo of a sexual nature," we can see three orange T-marks taped to the floor near her. (00:02:55)
Character mistake: In the scene, where Jeanne tells Tony that he never said he loves her, besides after sexual activities. This is not true. In episode 15 "Friends and lovers" Tony ends a phone call saying "I love you."
Visible crew/equipment: When Abby is going through the garbage to disprove Tim's sister you can see a crew member's foot in the screen- it's a brown boot.
Once a Hero - S4-E8
Revealing mistake: When Ducky opens the fridge door containing the suspected killer, the dead body's eye twitches. (00:21:00)
Continuity mistake: When McGee shows Abby the video, the first time it starts at 0:38, and when he shows it again it starts from 0:50. (00:19:00)
Factual error: The inspector is suffering from thallium poisoning. However, everyone is using various radiation detection methods to detect the thallium. Natural thallium is not radioactive. Of the artificial thallium, the only with a half-life long enough to last long enough to pose a problem is too weakly radioactive to be a significant hazard.
Visible crew/equipment: When Ducky and Jimmy start working on The Meat Puzzle, Ducky says, "Let's put Adam on the left and Eve on the right." In the next shot a crew member wearing a red shirt and khakis is visible at the right side of the screen. (00:05:55)
In the Dark - S4-E22
Visible crew/equipment: At the start, when Mr. Scott's assistant walks in, the T-mark is visible on the floor in front of the darkroom's door. (00:05:00)
Continuity mistake: Director Shepard has long nails with a French manicure, but when McGee gives her the envelope from Gibbs, in the closeup Jenny's nails are short and unpolished while she holds the old photo of herself. (00:43:10)
Continuity mistake: When the mule asks for a cast he is told after surgery. At this point he raises his hand above his head. Camera cuts and it's back by his side. (00:06:30)
Continuity mistake: When Jen is asking who's been in her study she points with her hand holding the letters at the end. Camera cuts and now she is holding the letters by the middle. (00:03:40)
In the Dark - S4-E22
Continuity mistake: Don explains what the investigation is about, and while doing so he has his hands clasped together. Camera changes and they are spread apart. (00:13:20)
