I'm really surprised that someone could get away with this on a long flight like LAX-SYD. Was he given any meals? Did he perhaps deprive someone who was legitimately in business class of their meal choice? Perhaps he was BSing about his success rate.
By the way, sometime within the last year, there was a news item reporting that former California governor Pete Wilson tried sneaking into a higher class than paid on a flight and was asked to move by the FA.
Kathy