The "penny in the door" incident from the pilot is referenced in this episode however is a paper clip instead of a penny.
According to the DVD commentary and production lore, if Scrubs had not been renewed for a second season (something the creators were almost sure would happen), it would have been revealed in this episode, as a series finale twist, that Janitor was a figment of J.D.'s imagination.
J.D.'s Girl Names: Charlotte.