Factual error: When Tim is tracing the British agent's mobile phone it shows that the number traced is a British land line number (01632) not a mobile number (starting 07...). The number is also seven digits long, not six as is the format in the UK.
Broken Arrow - S8-E7
Factual error: Ziva shows McGee her passport including her passport photo. In the photo she is smiling broadly. Regulations state that a passport photo must be a neutral facial expression. This photo would have been rejected. (00:01:50)
Factual error: When McGee tracks Mason's first phonecall, he says the line has been forwarded to a skype number. When he does the IP address shows up on the screen as 212.11.256.192. An IP never goes over 255. (00:11:40)
Answer: I hadn't seen the backdoor pilots yet but while it wasn't explicitly stated, at least onscreen, I heard somewhere Vivian got either fired from NCIS due to jeopardizing a case, got resigned from the agency, or transferred to the FBI.
Raykvega423