Factual error: The season 5 episode "Designated Target" deals with the murder of a Navy admiral and the cab driver transporting him through Rock Creek Park in Washington, DC. Late in the episode, the investigators try to get a lead on another cab driver by tapping into the records from taxi meters. The problem is, DC cabs don't yet have meters. Congress banned them in 1933, but legislation passed this year now gives the DC government authority to install meters. And in fact, just days before this episode aired in Nov 2007, DC's mayor announced plans to switch from the zone system to meters by April 2008.
Factual error: There is a flashback scene in this episode, where a young, dejected Abby Sciuto is walking along railroad tracks after failing to give the bear back to Ricki. This scene starts with a shot of the railroad tracks, then pans up to Abby. It can be seen that the rails are laid on concrete sleepers, with modern steel clips holding the rails to the sleepers. Given that the flashback appears to take place when she was at least a couple of decades younger (i.e. the mid-1990s), such modern methods of construction wouldn't have been used. A period-accurate railroad track would have wooden sleepers, spikes and lighter rail. As such, it's obvious that the producers just went to the nearest railroad tracks and filmed the scene there.
Revealing mistake: During season 4 the same television clip of President Bush and VP Cheney disembarking Air Force One is used on the background television in the squad room. In some cases the clip is running and not in unison, on three of the televisions in the same scene from shot to shot.
Continuity mistake: When Sharif calls Gibbs to gloat, when Sharif ends the call, the shot cuts to Gibbs closing his cell phone, shot cuts to McGee and Col. Mann, when it cuts back to Gibbs, he is closing his phone again. We can even hear the phone close both times.
Continuity mistake: During the scene where Tim and sister Sarah are working on the past evening's timeline, Sarah's clothes lying on the counter change position between the wide shots and the close-ups. Also the plastic her shoes are sitting on in the wide shots disappears in the close-up when she removes them and when she picks up the baggie of money. The screen shot of the locations in the time line also change locations. The 9:30 and 10:00 individual locations show up in the Georgetown University area but when they zoom out to show all three locations, the two time location now show the George Washington University, Foggy Bottom area of D. C., and it shows Tim's residence as being in Arlington National Cemetery.
Factual error: During the sequence where Bankston and Lee are supposed to make the dead drop of Domino, Adams Tavern, the location of the drop, is shown to be at 2177 Pimmit Drive in Woodbridge Va. The map that is showing the location is geographically correct, but "Pimmit Drive" is actually Horner Road. Also once the action leaves the bar, Lee and Bankston hijack a bus that reads "District Transit Authority". Since they are in Woodbridge, the bus service would be OmniLink.
Continuity mistake: In the scene where Tony and Ziva discover the dead body in Amanda's hiding place the dead body's extended arm is lying on the rug on the floor, and is left that way when Gibbs tell them to leave, yet in the next scene when Ducky shows Gibbs a picture of the dead body, the rug beneath the extended arm has disappeared.
Continuity mistake: During the investigation of the dead wife's crime scene, the arms of the corpse change position from shot to shot throughout the scene, including a moment where the corpse's arms are crossed, then in the next shot Ducky is shown crossing her arms. Ducky is also shown crossing the same arm twice, and the guitar control also changes direction and position with respect to the body.
Continuity mistake: When Tony's dad arrives at the NCIS office for Christmas, he is met at the elevator by Ziva. He is holding a Christmas present (which looks like a bouquet of flowers) with the 'red' end up. As the camera angle changes, he is now holding it 'red' side down.
Continuity mistake: When Tony & Ziva meet their contact in Naples, we see a local cop walking down the background behind them, and passing a walkway to the boat. Seconds later, as the camera changes view, we see that cop about 30 feet back, going the same way.