Untouchable - S3-E20
Deliberate mistake: When Tony's holding the cat's carrot toy he's nearly bitten, and the Probies laugh. Then while Tony directs his amusing fictional rant at one Probie, just as Tony asks, "Getting a kick out of this now, think this is funny?" this closeup is flipped. (00:08:50)
Visible crew/equipment: When Ziva is with Jason Edom in the interrogation room, Ziva sits down and asks him if he's afraid of germs. Then after Edom's closeup, the red T-mark is visible on the floor near the door in the wide shot. (00:31:55)
Visible crew/equipment: During the scenes in Lafferty's house, crew/camera movements are reflected on the large glass fish tank near the front door. (00:27:40 - 00:35:00)
Continuity mistake: When Gibbs asks Abby to estimate how much time Wilkerson has in the car trunk, just as Abby says, "Depends on the age of the car," this shot is flipped, note Abby's neck tattoo switches sides. (00:10:25)
Visible crew/equipment: When Gibbs tells Tony and Ziva to go to Wilkerson's home they pass Abby on their way to the elevator, and just as Ziva waves her hand at Abby, in this shot and a following shot a crew member is visible as he's ducking down by Tony's cubicle, under the monitor on the right side of the screen. (00:04:10)
Continuity mistake: While Gibbs and McGee are searching the dock area for Ziva and Tony they find the dead terrorist, and in all shots of the deceased his arms are raised, but in the one overhead long shot the arms are down by his sides. (00:23:25)
Visible crew/equipment: While Palmer and Ducky are with the deceased in Autopsy, just as Jimmy mentions that Keller only dated models and A-list celebrities, the reflections of the camera operator and camera are visible on the steel door. (00:26:40)
Visible crew/equipment: While Tony and Ziva are speaking with Tom Crawley about Taylor, the red and green tape marks are visible on the floor in overhead shots, such as when Crawley stands up. Also, near the end, while Gibbs, Ziva, and Tony are with Crawley and the models, more tape marks are visible again. (00:19:20)
Visible crew/equipment: After Gibbs threatens to take McGee's badge if he ever hesitates again, when it cuts to McGee at the lab with Abby, the chalk T-mark is visible on the floor at McGee's feet. (00:42:20)
Visible crew/equipment: While Gibbs flips the pages of the court records from Stewart's case, when he sees the photos he rushes off to the lab, and in the wide shot two green T-marks are visible on the floor, in front of his desk. (00:42:50)
Visible crew/equipment: When Gibbs brings the pizza to Tony at the jail, in the wide shot just as Tony walks over to Gibbs, a crew member wearing white shorts is visible behind Gibbs, on the right side of the screen (where another camera is located). (00:22:55)
Visible crew/equipment: After Abby demonstrates the magic shop knife to Gibbs, when it cuts to Tony surprising the suspect, the T-mark taped to the ground is visible behind the car in this shot and a following shot. (00:40:15)
Visible crew/equipment: After Ziva discovers the hair dye in the hotel room it cuts to McGee with Abby, and as they walk away from the desk, the reflections of crew members, including the dolly grip pulling the camera dolly, are visible on the glass door. (00:39:40)
Silver War - S3-E4
Visible crew/equipment: At the re-enactment field, after Ziva pulls a gun on the two men in the graveyard, it then cuts to McGee and Tony with Kearns while Gibbs is on his cell. Two shots later, the camera becomes visible on the right side of the screen, just as Gibbs walks past it. (00:40:45)
Mind Games - S3-E3
Visible crew/equipment: While Gibbs and Tony are in the car chasing after Briggs, Gibbs is on his cell with McGee getting location updates, and just as Gibbs asks, "How far ahead is he?" the camera is visible behind Gibbs and Tony, by the back seat. (00:37:55)
Mind Games - S3-E3
Revealing mistake: When O'Neill starts taking Polaroid photos of Cassidy in the barn, Cassidy's blouse is properly buttoned up, but the second photo O'Neill takes shows Cassidy's blouse is being held together with a large safety pin, then the buttons are intact again. (00:39:10)
Continuity mistake: We see Ziva take the photos out and place them on the interrogation table and ask the captain to point out their suspect. We then see the Captain pick up a photo. Camera changes to McGee and Tony behind the glass and we see Ziva getting the photos out and places them on the table again. (00:39:10)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.