Yankee White - S1-E1
Deliberate mistake: After the bad guy obtains a weapon from the armory on Air Force One, he pushes the door shut. It is heard to latch correctly, but a few seconds later when Special Agent Gibbs comes, the door is now seen to be slightly ajar. (00:38:55)
Yankee White - S1-E1
Deliberate mistake: Fornell doesn't recognize Gibbs, but subsequent episodes establish they have a long history together.
Untouchable - S3-E20
Deliberate mistake: When Tony's holding the cat's carrot toy he's nearly bitten, and the Probies laugh. Then while Tony directs his amusing fictional rant at one Probie, just as Tony asks, "Getting a kick out of this now, think this is funny?" this closeup is flipped. (00:08:50)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.