Continuity mistake: Tony boards a helicopter to go to Puerto Rico. When he lands, it's a different one. The first has the number 406 on its side.
Continuity mistake: When DiNozzo rings Gibbs, we can see Kate taking metal scrapings on a pole that has tape on it just above her hands. When we get a closeup of Kate, the tape is not there. (00:25:50)
Continuity mistake: When the lady at the base exchange is throwing stuff at Tony, Tony has a yellow shirt in his hands that disappears, only to be thrown again. (00:24:00)
Revealing mistake: Just after Agent Todd is seen going through the diary, there is a shot of the ship sailing past the camera. However the number 51 on the side of the ship is backwards, showing the shot is flipped. (00:30:20)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.