Revealing mistake: When Ducky opens the fridge and uncovers the body, the man's eyes twitch. (00:21:20)
Continuity mistake: We see Jenny talking to the former embassy worker. When doing so she has her hands out stretched in one shot and clasped in others. (00:25:30)
Continuity mistake: In one scene, Tony observes that Ziva never uses contractions when she talks, and Ziva even seems confused as to what they are. But in previous episodes, Ziva not only knows what contractions are, but uses them frequently.
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.