Visible crew/equipment: When Dr. Mallard is talking to Mr. Palmer about a "White Elephant", you can briefly see crew members on the stainless steel door on the left of the screen. They are blurry, but distinguishable. (00:23:55)
Revealing mistake: Kate pulls the record up on the screen near the start and there is some writing on the file. This is a copy of the file she has in her hands. However the writing on the file as seen on the screen is Kate's next few lines. (00:09:30)
Continuity mistake: When McGee finds out about the poison ivy, he is holding the bat in 1 hand. Camera cuts and he is holding it in 2 hands. (00:16:20)
Continuity mistake: Just after seeing Ducky, McGee is talking to Abby. He pulls a face due to his current situation, the camera cuts, and his facial expression is completely different. (00:26:50)
Audio problem: When Moore's widow sees her lover being brought in, she shouts "Roger!" - but her lips don't move. (00:33:05)
Continuity mistake: When the SGT is in the interrogation room, as Gibbs sits down, the SGT's hands are on the table. Camera cuts to Gibbs sitting down, but look behind him at the mirror and the Sargent's hands are not on the table in the reflection. (00:33:20)
Continuity mistake: When Mrs. Moore is in the interrogation room, her hands are flat on the table then clenched instantly. (00:34:00)
Other mistake: It's the same license plate (107TIX) on Runyon's truck when the video footage is enhanced by Abby as the Ford sedan in S2 E10 "Chained" when Dinnozo and Jeffery leave the cabin.
Continuity mistake: At the start, the woman has a magazine folded under her arm with a purple article facing up. Camera cuts and now it's a yellow article facing up. (00:00:25)
Continuity mistake: When the team is talking to the woman in red, they walk past the mail boxes. Camera cuts and they walk past the mail box again. (00:05:00)
Bikini Wax - S2-E18
Visible crew/equipment: When Gibbs joins Caitlin on the beach just as she finishes up her call, in the wide shots their two reddish T-marks (plastic type) are visible on the sand, where each of them stand. (00:06:20)
Bikini Wax - S2-E18
Continuity mistake: When Palmer and Ducky are talking in the toilet, the one door is closed in one shot and ajar in a second. (00:08:20)
Bikini Wax - S2-E18
Visible crew/equipment: When enquiring about the rims, a camera is reflected in the paintwork of the truck. (00:25:20)
Bikini Wax - S2-E18
Continuity mistake: When Gibbs shows his identification to Jonathan Redding's supervisor, he holds the badge from the top of the wallet, then at the bottom, then back at the top. (00:26:40)
Bikini Wax - S2-E18
Audio problem: When Abby tells McGee to shut up near the end, the audio is out of sync with her mouth. (00:34:40)
Continuity mistake: Gibbs puts his gun in his drawer on a blue folder then goes to talk to Fornell in the lift. When he comes back, he picks his gun up and the contents of the drawer and position of the gun have completely changed. (00:14:50 - 00:16:50)
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