Commonwealth Bank chief executive Matt Comyn isn’t quite in “I told you so” mode, but he does admit he’s found comments made by his biggest rivals in the past week about unsustainable margins in the mortgage business “almost bemusing”.

Comyn started banging the drum on loss-making mortgages early last year. Last November, as rivals and analysts questioned CBA’s strategy of deliberately stepping back from the market due to intense competition, he memorably described the fall in ANZ’s margins as a result of it aggressively chasing home loans as “the largest margin erosion in the history of Australian banks”.