Factual error: In the shot where Mac discovers Adam's details on the killer's desk, under Adam's name is what is supposed to be Adam's computer IP address. Although the first two octets 172.16 are a plausible address, within a private address range, the third octet is a little too high at 450 (the largest number in an octet is 255) and the fourth octet at over 1000, well.
Factual error: During their investigation, the CSIs learn that their murder suspect is in the witness protection program, under FBI protection. WITSEC falls under the jurisdiction of the United States Marshals Service, not the FBI. And considering how many protected witnesses the Marshals Service relocates each year, it's doubtful they would be shorthanded enough to need help from another agency to locate a missing witness.
Chosen answer: Probably to broaden the scope of the show's plot and give the audience a chance to see the characters in a different setting, People act differently at home from the way they do at their workplace. By the ninth season, the characters would have become overly familiar and predictable. It gives the writers a chance to do something different with them.
raywest ★