There was no need for Rudy to be "happy" at all. That wasn't an interview -- it was basically a Giuliani campaign ad in which Hannity played the role of a campaign prop.
Hannity had no intention of asking him any tough questions. In fact, the "interview" reached the point of being comical once Hannity started providing answers for Giuliani in the form of his "questions."
pawn vanity is good at being a campaign prop