Continuity mistake: At the start we see Saleem load up the syringe of truth serum and there is very little in the syringe. When he sticks it into Tony, the amount of serum has more than doubled. (00:01:15)
Continuity mistake: When Saleem kicks McGee at the start, McGee's feet swap position between camera angles. (00:01:40)
Continuity mistake: Saleem's grip on Tony's badge changes from a couple of fingers to the whole hand. (00:02:50)
Continuity mistake: When we see Demarco fighting on the ship he has a knife sticking out of his legs that keeps disappearing and reappearing. (00:04:00)
Continuity mistake: When the DEA agent walks up to Tony she stretches her hand out and her fingers are held together neatly, Camera changes and her fingers are open. (00:11:00)
Continuity mistake: The way Claire holds her power putty changes from a clasped hand to a couple of fingers between shots. (00:11:00)
Visible crew/equipment: When interviewing the DEA agent, there is a green reflection and a tripod stand reflected in her glasses. (00:11:40)
Continuity mistake: When McGee and Tony are discussing Ziva while leaning on the car, their hands are constantly moving between shots. (00:20:45)
Continuity mistake: We finally see that it is McGee tied up on the floor. When he is rolled over to see his face, there is a cigarette butt on the floor by his head. When the camera next shows him the butt has gone. (00:21:50)
Continuity mistake: When Tony is walking around Abby's lab, his jacket is constantly switching from buttoned to unbuttoned. (00:22:45)
Continuity mistake: When Abby says that Ziva is uniformly absent, she has her hands out of shot. Camera changes and you can see her pointing at Tony and McGee which should have been visible in the previous shot. (00:24:20)
Continuity mistake: When Heather comes in to talk to Tony, his grip on his phone receiver changes instantly. (00:24:20)
Continuity mistake: When Gibbs and Tony leave their respective rooms we see Gibbs close his door via the monitor in Tony's room. However when they emerge into the hallways Gibbs shuts his door again. (00:26:15)
Continuity mistake: When we see Ziva talking to Tony, she has some hair across her face that is constantly disappearing and reappearing. (00:32:15)
Plot hole: We see Gibbs fire his sniper rifle and kill Saleem from a hill several hundred meters away over hilly and sandy terrain. We then see him shoot a guard while Tony and McGee are getting free. By the time they have walked down the corridor (about a minute) Gibbs has appeared in the hallway in full desert sniper suit. (00:40:00)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.