If they'd really wanted to be accurate about it, all they had to do was describe his role as 'Invisible Man.' http://imdb.com/title/tt0417056/fullcredits#cast
Just scroll down. You'll see it. Or not. In fact, if you don't see it, you've pretty much figured out who it is.
So if you've ever wondered where a reality show appearance might lead you, here's the answer: it leads to Paris Hilton. Be very, very afraid.