Character mistake: When Gibbs tells William Danforth that the body in autopsy isn't his son, he says, "Not according to AFIS." AFIS is the fingerprint database; since the body was identified using DNA, Gibbs meant to say "CODIS." (00:13:50)
Continuity mistake: When Gibbs and the director sit down for the Chinese food, she picks up her fork and places it into some food. Camera cuts and now she is reaching across the table. (00:32:20)
Continuity mistake: When Ducky is explaining what happened, Palmer is taking his right glove off. Camera changes and now he is taking his left glove off. (00:05:50)
Continuity mistake: When Ziva tells Tony to get on with the work she is looking downwards. Camera changes and she is looking upwards. (00:04:50)
Continuity mistake: At the very, very start we see a clipboard on the trolley with the clip to the left. As the camera changes to outside the clip is now on the right. (00:00:05)
Visible crew/equipment: After Ducky tells Gibbs he has little chance of ID'ing the burnt body, as Gibbs leaves Autopsy, two crewmen and a camera are visible reflected in the metallic door frame. (00:35:20)
Continuity mistake: When Abby and Gibbs determine that the ambulance exploding wasn't an accident, McGee is visible next to Gibbs. He then mysteriously disappears, and a moment later, walks around the ambulance carrying an evidence baggy. (00:08:15)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.