Visible crew/equipment: When Gibbs is on the phone with Sharif, Gibbs asks him, "Who were they? Wife? Family?" and just as he says the word "wife" we can see an actor's red tape mark on the floor at the corner of DiNozzo's desk, which wasn't there a minute earlier when McGee walked over to DiNozzo. (00:31:30 - 00:32:45)
Visible crew/equipment: When Ducky and Jimmy start working on The Meat Puzzle, Ducky says, "Let's put Adam on the left and Eve on the right." In the next shot a crew member wearing a red shirt and khakis is visible at the right side of the screen. (00:05:55)
Cover Story - S4-E20
Visible crew/equipment: At the very start, as the fire truck pulls up you can see a crew member pushing a trolley with a camera on reflected in the paintwork. (00:00:05)
In the Dark - S4-E22
Visible crew/equipment: At the start, when Mr. Scott's assistant walks in, the T-mark is visible on the floor in front of the darkroom's door. (00:05:00)
In the Dark - S4-E22
Visible crew/equipment: When Don explains how he was about to call NCIS, he leans over to get a folder out. When he does, the camera shadow can be seen moving along the back of his head. (00:13:50)
Visible crew/equipment: When the car pulls away from the airport at the start the crew are reflected in the paintwork. (00:00:40)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.