Character mistake: In the scene, where Jeanne tells Tony that he never said he loves her, besides after sexual activities. This is not true. In episode 15 "Friends and lovers" Tony ends a phone call saying "I love you."
Continuity mistake: When Gibbs is at the batting cage with Col. Mann, he raises his bat, ready to swing. In the next shot, his arms are down by his side and he raises the bat again. (00:02:30)
Continuity mistake: Tony removes his cigar from his mouth using his right hand. Camera changes and now he has his torch in his right hand. (00:24:30)
Cover Story - S4-E20
Visible crew/equipment: At the very start, as the fire truck pulls up you can see a crew member pushing a trolley with a camera on reflected in the paintwork. (00:00:05)
Cover Story - S4-E20
Continuity mistake: The way Ducky holds the dictaphone changes between shots. (00:13:45)
Cover Story - S4-E20
Revealing mistake: When Ducky is holding the dictaphone, it is off as the display is blank. (00:13:45)
Cover Story - S4-E20
Continuity mistake: Just as Ducky is finishing reading the letter out loud to Gibbs, he has the letter in both hands. Camera cuts and now he is holding it in one hand. The Dictaphone also appears on the table instead of in his hand. (00:13:50)
Cover Story - S4-E20
Continuity mistake: When Todd is arrested, he has his hands behind his head. Camera cuts and now they are shoulder height. (00:28:00)
Cover Story - S4-E20
Continuity mistake: When McGee is free-writing, the stuff he has styped changes between the two close ups. While the words remain the same, the spelling and punctuation changes. "Was" becomes "Wsa", "Gat" becomes "gat", "desser" becomes "des" and "Bang" becomes "bang". (00:33:40)
Cover Story - S4-E20
Continuity mistake: When McGee is writing, we see he is working on a new paragraph. Camera cuts away for 6 seconds and then cuts back and now he is already halfway through the third line of that paragraph despite there not being enough time or enough pings of the typewriter resetting. (00:33:50)
Cover Story - S4-E20
Continuity mistake: We see Abby's phone lit up and ringing. Camera cuts and now it's no longer illuminated but still ringing. (00:37:00)
Continuity mistake: When Abby chucks the polystyrene in the box, its position changes between shots. (00:18:10)
In the Dark - S4-E22
Visible crew/equipment: At the start, when Mr. Scott's assistant walks in, the T-mark is visible on the floor in front of the darkroom's door. (00:05:00)
In the Dark - S4-E22
Revealing mistake: When Tony is telling Gibbs & Ducky that Abby got a hit on the dead sailor's fingerprints, Gibbs takes the file from Tony; the camera shows the file, which appears to be a legitimate profile sheet, but in the comments section, is the script that Tony just read aloud. (00:07:36)
In the Dark - S4-E22
Continuity mistake: When Ducky finds agent Lee's bra, he has some sticky labels in his hand in one shot and not in the next. (00:08:15)
In the Dark - S4-E22
Audio problem: When Abby is saying how she quit caffeine, the audio in the long shot doesn't match up with her mouth and is a clear overdub. (00:10:40)
