Continuity mistake: The second time we see McGee bidding on clubs there is 1m 24s remaining. 3 seconds later he closes the window when Gibbs walks in, and there is 1m 24s still left. (00:21:00)
Continuity mistake: When Gibbs asks the kid where he got the gun, he has a notepad in his hand. Camera cuts and it's now a pen. (00:05:25)
Continuity mistake: When looking at the playboy magazine at the start, the pages change between shots. (00:01:50)
Chosen answer: It is never stated, however she must have been there several years if she is on presidential detail.