It's by no means certain that this was leaked by Rudd. As you said there were 3 people in the room, one of whom was Senator Faulkner who announced his retirement shortly after the leadership change. Equally it's possible the leak came from a Rudd supporter disgruntled at seeing his leader toppled. Rudd himself has little to gain from this leak: It serves only to jeopardise his post election place in the ministry.
