Ducky talked of the Guillotine as invented by Dr Joseph-Ignace Guillotin. Although he proposed its use as a humane method, the machine was invented by Antoine Louis and was first called the louisette.
Ziva asked about the "nation of Nevis". Nevis is not independent, but one of the two parts of the Federation of St Kitts and Nevis.
In two scenes a computer record on a monitor screen shows the address of Martin Broussard in "Petersberg", Virginia, whereas the correct spelling is "Petersburg" with a U.
When Gibbs places the two service record printouts in front of a Petty Officer he is about to interrogate, they show two different service members with the same Social Security Number.
The data on the personnel files of Seaman Randall and PO Jones are identical. Same files, different photographs. The files mistakenly identifies their rank as Lt Commander.
In the scene where Ducky realizes who the bad guy is, the camera is behind Ducky's head, with the bad guy on screen, standing with the coolers behind him. The reflection shows that of a crew member as there isn't anyone else in this scene, yet. Jimmy was there, but this person couldn't be Jimmy, as it appears they are dressed in a red jacket, jeans and boots. The camera is also reflected for a brief second.
The Director says, "Reminds me of our op in the former Czech Republic." There is no "former Czech Republic". There's the current Czech Republic. There's the former Czechoslovakia.