Plot hole: A large part of Nick's plotline revolves around the discovery that the couple's stolen ring has a fake diamond switched out for the real one. But the ring was left as collateral for a very expensive necklace for the woman to wear that night. There is no way that a jewelery store would accept a ring for collateral without appraising the ring's/stone's value first. And in that inspection, they would have discovered the switch and not accepted it.
Continuity mistake: When Sara is showing Greg the route the old woman took in her car, she draws a blue line on the screen with her finger. When she says something about turning left she draws a continuous line to the "Meadows Lane," but when the shot changes and goes back the line is broken into two.
Factual error: Grissom does a quick analysis on the rough diamonds (chemical or laser) and immediately identifies the region of origin for the diamonds. He and Catherine then postulate that the diamonds are conflict diamonds. There is no way to identify the country or region of origin through any type of analysis. The United Nations and the world's diamond industry are looking for a way. http://www.reliefweb.int/library/documents/conflictdiamonds.htm http://pubs.acs.org/hotartcl/cenear/010212/7907sci1.html http://www.whitefirejewelry.com/wfbb/viewtopic.php?p=88&sid=b0e62206a64d98c81e53b600e053582f.
Continuity mistake: At one point Catherine is at the coffee shop and the parents of a murdered girl come to talk to her. She is holding her coffee in the right hand and her cell phone rings and she grabs it with her left. The shot switches angles while Catherine is talking and her cell phone has magically shifted to her right hand.
Continuity mistake: In the bit where Nick and Warrick decide who is going in the pool, Nick loses and begins to remove his top while still wearing his latex gloves. The camera switches to a different angle and while he is still taking his top off, his gloves have disappeared.
Plot hole: While searching through the dead computer guy's CDs Nick finds a CD supposedly burned that night, containing data gathered at the time of death, but by the time the CD was burned the guy would have already been dead, so who took it out of the computer and filed it away?
Other mistake: Just after they arrest the Janitor, they are walking out of the building past the employee's. The girl sitting at her chair is not actually typing on her keyboard, her fingers never even press on the keys and her screen-saver is displayed on the screen. (00:37:15)
Other mistake: Stokes tells "Michaelangelo" he is looking for a blue Honda, blue rims, blue tint. The picture Michaelangelo shows Stokes and Willows is an Acura RSX, not a blue Honda. (Note: The red Honda that the victim was driving is not the one that Stokes is looking for.) Just because the two car brands are owned by the same parent company does not mean that they are interchangeable when describing them. You certainly couldn't call a Cadillac a GM and not be considered wrong even though they are both made by the same parent company (GM).
Factual error: When Grissom calls Greg into his office to ask him about his Scandinavian heritage, Greg says his grandfather was kicked out of Norway for getting his grandmother pregnant before they were married. Norway did not kick people out of country for that reason. Anyone who does family research will see that 7 out of 10 times a child was born out of wedlock or illegitimate, and nothing was done about it. It is recorded in the church records and that is it, there were lots of reasons this happened that children were born to unwed parents. Main reason was that they applied to be married and the marriage was disapproved of for one reason or another. Europeans are not as prudish as Americans about this stuff. A lot of Scandinavians nowadays live together, have kids and never get married.