 Even though the episode aired during the beginning of the fifth season , it was produced by the crew of the fourth season . A large part of the original crew left the show after season four . This led to the addition of several scenes , which normally would not have been considered , because the mentality of the departing crew was " what are they going to do , get us fired ? " Although most of the episode was completed by the staff of season four , the end was rewritten by the team of season five . 
