Visible crew/equipment: When Gibbs and Ziva are in the "safehouse" Ziva set up for Ari, a crew member and his boom microphone are seen on the left of the screen, right before Gibbs climbs the ladder to remove the hidden camera spying on them. (00:30:10)
Other mistake: When the old well needs filling in, for safety reasons, Ryan is breaking up bricks. If you are filling up a well, first, you'd need lots of bricks and stones, heaps more than Ryan's small pile, and, two, why does Ryan have to break up the bricks? They're going into the well - it doesn't matter if they are big or small.
Revealing mistake: When Danny is driving Mr. Zhao in his convertible at night, you can really see that the background is a bad fake and since even though Danny is driving with the top down, his hair and clothing does not get ruffled at all by the wind.
Thrill Kill - S5-E1
Factual error: When Dylan gets out of jail, a palm tree can be seen in the background behind him. This reveals that the scene was filmed in Los Angeles, not Philadelphia.
Fastest Criminal in Reno - S3-E5
Continuity mistake: When Fast Eddie jumps over the road block and comes crashing down you can see from the severity of the landing that the front left side of the vehicle is seriously damaged as is probably the rest of the front of the vehicle. However when the camera shows the shock on the Officers faces of what's taken place and then pans back as Fast Eddie drives away, his car shows no damage whatsoever.
Beauty and the Obese: Part 1 - S1-E1
Continuity mistake: The stripper in blue and yellow has some men watching her and are very close to her stage/table. The men on the left have no drinks or anything else in front of them. A few moments later after she takes her top off, it shows the man in a bow tie and the guy in a beanie sitting there still, but suddenly they are at a small table with drinks. Also the people around them vanish and a dog appears. (00:01:54)