Factual error: Dry ice sublimates at -78.5 C. That gas is going to be very, very cold and it will rapidly bring the temperature of the room down to a very uncomfortable level. Before a sleeping person suffocates they would be woken by the freezing cold.
Factual error: The murderer kills the two students by drilling a hole through the adjoining wall of the victim's room at floor level, placing 40lbs of dry ice next to the hole, and allowing the sublimating carbon dioxide to pass through the hole into the victim's room and creating a toxic atmosphere. Since the two rooms are at the same air pressure, the only possible way for the CO2 to move from one room to the next is to be pumped through. As neither room has an excessive level of carbon dioxide in the atmosphere the sublimating gas would fill both rooms until the CO2 levels in both rooms was the same.
Plot hole: The bodies were pink because of exposure to the lower temperatures created by the dry ice venting into the room. None of the CSI team noticed a chill when they entered the room? None of them noticed the bodies were cold to the touch? No one noticed that the body or liver temperatures didn't match with the estimated time of death?
Continuity mistake: In the opening scene, the female student is wearing green panties. When the two bodies are found, she is wearing red panties. It was a murder behind a locked door, so no one changed them for her.
Suggested correction: The girl had green panties with pink or red strings. When she was found, all that was visible was the string.
Visible crew/equipment: When David, Warrick and Catherine are standing in the crop circle discussing how the body ended up there, when David says "I have an idea", Warrick looks up slightly and you can see the boom mike reflected in his sunglasses.
