When Nick comes in to Grissom's office, setting off Grissom's "Big Mouth Billy Bass", the fish on the wall alternates positions in between shots and can be singing when no song is heard and can be still when he's singing and there is music.
When Nick and Kristy are in the parking lot, Kristy is leaning against the door to her car as Nick explains DNA. As Nick leaves the scene after Kristy kisses his cheek, the sound of a car door opening is heard but the door was already open as Kristy was leaning on it while she was outside with Nick. She did not have time to close it in between the shot of her leaning on the door and kissing Nick's cheek as she thanked him.
While hiding a pistol inside a PC is probably not very good for the latter's long term operation, it is extremely unlikely that it would prevent the PC from even starting up, much less provide a cause for a power-on self test error.
It might seem like there is hardly "tens of thousands of dollars of hi-tech computer equipment" on the desk; there is just an ordinary simple few-hundred-dollar Compaq-grade PC work-station there. However, in 2000, there was not such thing as a "few-hundred-dollar Compaq-grade PC". Even a basic computer and monitor system could run to three or four thousand dollars.
When Greg checked the paper cut-out of the shirt for spit, the spit is located high on the chest. It was a very low cut shirt, so there should be a large void with no spit, there definitely wouldn't have been evidence that high.
None of the red "here's one of our trucks" marks on the screen actually disappear when the employee does the first "show the reefer trucks only" elimination; all of the marks on the screen just flicker on and off once.
In several scenes, Kristy Hopkin's dialogue doesn't match her lip movement due to obvious overdubbing.
In Season 1: Episode 8 "Anonymous", Grissom states that he "always wears gloves at every crime scene". However, when he and Catherine are searching the cab of an 18-wheeler, Grissom's hands can be clearly seen without gloves. A seasoned forensic scientist like Grissom, who pays such strict attention to detail, would not make such a rookie mistake.
When asking the trucking company representative to track the trucks in order to find the one they are searching for, Grissom asks, "Can you narrow your database?" Eliminating trucks that don't fit the CSIs' criteria does not change the size of, or "narrow," the database itself, that is, the total number of trucks; it only narrows the search results based on the change in search criteria. Grissom is not expected to be that knowledgeable about these matters.