Based on this article it would appear Mr Debelle is earning in the vicinity of $500-600k (?) per annum. I'd probably sleep like a baby on that sort of money too. I could save up for 2 years and buy a home outright without need for a mortgage. Further to this his job is practically recession proof.
Put Mr Debelle on a $60k income in a $500k house with a $450k mortgage with the potential for the value to drop substantially below his equity and watch his concern about the housing market grow...