When Morgan says that Gideon is having a nervous breakdown, Gideon walks back into the room and tells him, "they don't call them nervous breakdowns anymore", to which Reid says they call them depressive episodes. This is also incorrect. The correct term in major depressive disorder.
When Reid and Morgan are trying to figure out the computer password, they pull Metallica's "Some Kind of Monster" out of the CD tray, and Reid guesses that the password is "Enter Sandman", but that track is not on that CD. So it's not possible for the killer to listen to that track when falling asleep. (When Reid suggests "Enter Sandman" it is in response to Morgan saying "I'm an insomniac who listens to Metallica to fall asleep at night. What song could possibly speak to me?" Also the CD is in the laptop computer. When Morgan lays down on the bed he reaches over his head and pulls down a portable CD player with headphones, which is probably what Richard listens to while trying to fall asleep.)