Conversation so far:
Are there any other interesting aspects about this article?
it also fell upon McMahon during the early years of Carson's tenure (when the show ran 105 minutes) to host the first fifteen minutes of Tonight.
Why did it fall upon McMahons shoulders?
substituting for Carson during a week of programs that aired between July 29 and August 2, 1963, and again for two nights in October 1963.
What caused McMahon to leave The Tonight Show?
CANNOTANSWER.
What was McMahons official role?
McMahon introduced the show with a drawn-out "Heeere's Johnny!.
Did McMahon release any statements about his time on The Tonight Show?
McMahon once told an interviewer that after his many decades as an emcee, he would still get "butterflies" in his stomach every time.

Question: Did McMahon obtain more air time while on the show?
Self-contained rewrite: Did McMahon obtain more air time while on the Tonight Show?