The pretape disclaimer at the top of the show was because all of Harrison's segments had to be taped earlier in the week due to a conflict. (I don't recall if the Madeline Kahn/Carly Simon episode started with a similar disclaimer, but Carly's performance that week was also pre-taped, due to stage fright or some damn thing. Having Chevy there to sing backup on "You're So Vain" also seems scarily appropriate.)
The pretape disclaimer at the top of the show was because all of Harrison's segments had to be taped earlier in the week due to a conflict. (I don't recall if the Madeline Kahn/Carly Simon episode started with a similar disclaimer, but Carly's performance that week was also pre-taped, due to stage fright or some damn thing. Having Chevy there to sing backup on "You're So Vain" also seems scarily appropriate.)