Revealing mistake: At the crime scene we see Gibbs making notes on his notepad prior to Ducky calling him over. When he's looking at the business card you can see his notes in his notepad. However his notes are all just random lines and squiggles. It's not the case that he's made notes for himself in his own writing style. (00:04:00)
Agent Afloat - S6-E2
Revealing mistake: When the officers wife is found dead at the start, look at her chest to see her still breathing. (00:03:20)
Revealing mistake: We see a close up of the money in the truck and the $100 note has got "This bill is for motion picture use only" printed on it. (00:05:40)
Revealing mistake: Agent Lang takes a picture of a debit card inside the first victims car which is a clearly prop. The name is "Jane Doe", and the card number is 1234-5678-9101-1112. (00:05:40)
Murder 2.0 - S6-E6
Revealing mistake: When the NCIS team were directed to the first video, McGee states that they were the first to view the video, however, the view counter on the video said 531,817 views. (00:06:40 - 00:07:15)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.