Continuity mistake: At the very start, the way the soldier is holding up the car changes between shots. In some shots, he is holding bottom left, in others, he is holding bottom right. (00:01:10)
Continuity mistake: When DiNozzo is asking, "When was the last time Ms Fenton saw Mr Kersey?" his hand is constantly changing position between instant cuts. (00:13:10)
Continuity mistake: Ziva tells Tony to stop being nice to her when doing the stakeout. When she does, in one shot her arm is on the car window, in the next shot it's not, then it's back again. (00:29:20)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.