Continuity mistake: In episode 8-1 Dead Doll: When Warick finds the zip-tie in the trunk it is not looped, when he holds it up for Grissom it is looped. He would not have looped it himself.
Factual error: In the episode where the worker got electrocuted in a construction site the main character, before replaying the victim's fall, says that "terminal velocity is 9.8 seconds squared". What he should have said was that acceleration due to gravity is 9.8 meters per second squared.
Continuity mistake: While Sara is looking through missing person's files, Grissom comes in and starts talking to her. One shot her hair is in front of her face, the next it's behind her ear. This continues throughout the scene. (00:22:05)
Factual error: When they are explaining why a nail was hammered into the electrocuted workman's boot, it is said that cars are protected from lightning strikes because they are insulated from the ground by their tires. Actually, tires conduct electricity, because they contain carbon (see: http://cartalk.cars.com/Columns/Archive/1994/November/11.html). Cars are actually protected from lightning by the Faraday Cage effect, which is explained on http://www.physics.gla.ac.uk/~kskeldon/PubSci/exhibits/E3/. Not a mistake CSI scientists would make.
Blood Drops - S1-E7
Factual error: The show falls into the Hollywood myth on polygraphs. Jesse is given a polygraph test after pleading guilty to the 4 murders. He answers all questions, except the last one, honestly. The 4 traces on the polygraph show no real movement on these questions. On the final question, Jesse lies and all 4 traces spike. If polygraphs actually did that, they would be admissible in court. But the reality is, it is the opinion of a highly trained operator that decides if there is a lie. The average person could not look at a polygraph results and point out a lie. There is no huge, visible spike. The producers could have replaced the 4 traces with a red\green light: Green is an honest answer and red a lie.
Revealing mistake: As they recover the car from the canal and open the door to reveal the girls dead mother, you can see her still breathing as they lie her on her back to examine her.
Continuity mistake: When Holly is first in Grissom's office and says that she feels light headed, Grissom offers her a chocolate-covered grasshopper and takes one for himself. Holly asks, "Is there a grasshopper in there?" and Grissom's right hand is near his waist. When the shot changes, Grissom merely smiles and eats the grasshopper, but his hand started off much closer to his chin without there being an opportunity for him to move it.
Continuity mistake: When Sara and Warrick are interviewing Meg at the end of the episode, the scene cuts between a medium shot of the dynamic duo, a close up of Meg's face and a close up of her hands which remain clasped on the table. The first time we cut to Meg there are tears in her eyes, but her face is dry. The second time we cut to Meg, there is a drying tear track on her right cheek. The third time we cut back to her, the tear track is gone, but there is a tear halfway down her left cheek. This continues throughout the scene.
Blood Drops - S1-E7
Continuity mistake: At the end, when Tina is shown the photos of Brenda they are in a pile of three. The camera cuts to a long shot and there are two in a row. Cut back to Tina and they are a pile of three again. This happens on and off throughout the scene.
Factual error: In the scene where Grissom is talking to the coroner about the bully who was shot, they talk about how the bully had "Dextrocardia" which is why all his organs are a mirror image of normality e.g. heart on right and liver on left. In actual fact Dextrocardia is only when the heart is on the right rather than left, the actual condition Grissom should have said was "Situs Inversus" not "Dextrocardia."
$35K O.B.O. - S1-E18
Continuity mistake: In one shot Grissom puts a shoe on its side with a pencil. In the next shot the shoe is upright again.
Factual error: Sanders is seen in the burn victim's OR, during debridement, wearing his street clothes (under a paper apron), and no mask or hat. Considering that the woman's skin is practically one continuous open wound, and her immune system is in an exceedingly fragile state, there's no way a breach of sterility like that would be allowed.
Homebodies - S4-E3
Continuity mistake: When Brass and Grissom are interrogating the stoned nephew, shots of Grissom from the front show him with his head leaning against his right hand and then moving his hand down to the table, then it cuts to a shot from behind and his head is still leaning against his hand. This happens twice during the sequence.
Factual error: Grissom sets up a little experiment to see if the deceased's blood is conductive to electricity. All are amazed when the blood does conduct electricity. All blood is naturally conductive. As a matter of fact, cardiac output is measured as a function of blood conductivity.
Revealing mistake: When the CSI from Miami and Catherine are in the autopsy, the guy goes to take a sample from the eyes of the dead woman. When he moves the swab towards her eye, you can see the actress' top eyelid move instinctively. She's supposed to have been dead for hours.
Continuity mistake: When Catherine and Warrick are testing to find the distance the shots were fired from, when Catherine shoots at the shirt that's 2 feet away there is no gunpowder around the hole. When Warrick puts the victim's shirt next to it, for comparison, there is now an inch of gunpowder around the hole.
Dead Ringer - S4-E20
Continuity mistake: When Nick is showing the burger guy the pictures from the ATM, he holds one up while facing the see-through window. He turns and puts it on the table and it's a completely different picture.
Audio problem: When the Ranger is talking about shooting a coyote he says, "I took care of him." The shot is from behind and slightly to the right of the Ranger. When he says this line, his mouth is not moving.
Revealing mistake: While the morgue's examiner opens Johnson's right eye with his fingers, the "corpse's" eyelid twitches repeatedly. (00:12:30)
You Kill Me - S8-E8
Continuity mistake: In Episode 8-08, "You Kill Me," when Archie takes the first kilo of cocaine out of the case, he takes the bottom-most left-most kilo. When he takes out the second kilo, he removes the same package with the empty space being two to the left of the one he would have removed.