Plot hole: Grissom examines the victim's body and immediately rules it a homicide because he was wearing eyeglasses. He states that suicide is a cowardly act and no coward wants to see their death and would have removed their glasses before committing suicide. What a completely unfounded, and unscientific, statement. Suicide being an act of cowardice is his opinion and not a scientific fact and they don't work off opinions: they always state how they work off the evidence.
Plot hole: A head without a body is found early in the show. Then, a body that has been decapitated, skinned, and severed of hands and feet is found. The CSI team assume the two are related until the coroner states that the body isn't even human. He also mentions that he has no idea what kind of animal it is and they'll need to consult an anthropologist. Everyone is shocked to learn the body is that of a gorilla. The body is humanoid (2 arms, 2 legs). It is larger than human size. The only thing it can possibly be is a gorilla. It must be a primate for having a humanoid shape and must be a gorilla because that is the only primate larger than man. There was no need to bring in an anthropologist (which should have been a zoologist if they truly had NO idea what kind of animal it was). It should have been painfully obvious to the CSI team, who are experts in all fields, that the body was a gorilla.