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)
Continuity mistake: The year Gibbs joined NCIS is inconsistent. It is revealed in this episode that he joined the NIS in 1992, the same year it became NCIS. But in the JAG crossover episode "Ice Queen", Gibbs tells Commander Rabb that he has been an agent for 19 years, which suggests that Gibbs joined NIS in 1984. And in "Singled Out" in season 4, McGee mentions that Gibbs has been an agent for roughly 16 Years, which would put Gibbs' joining NIS in 1990.
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.