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.
Continuity mistake: When Sara is trying to match up bite plates. In the first two close-up shots of Sara's face, you can see an out-of-focus shot of Greg's sleeve on the right side of the screen, seconds before he actually appears in the scene.
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.