Cost of funding - cheap and risky?

More on Oz banks' low cost of funding - it's due to nice instruments called covered bonds, invented in the former European state of Prussia in the 18th Centure and rolled out globally in the 2007-8 financial crisis:

....Now the evidence is in. Covered bonds have brought down bank costs even further. In a confidential note to its institutional clients, Westpac describes the fall in wholesale funding costs over the past year as ''extraordinary''.....No longer can the banks rely on that hoary old chestnut of ''high funding costs'' to pass off their failure to match the successive cuts in the official cash rate....Margins are fatter than ever, veritably bulging, and there is scant proof that borrowers are getting their grimy fingers on a single cent of it. It's a good thing for shareholders though, some cautious at the listless growth in credit....(here).

But like all good things in banking, risks are appearing...

....BlackRock Inc. said using loans to small- and medium-sized companies, or SMEs, to back the securities rather than safer real estate or public-sector debt may devalue the asset class. Pacific Investment Management Co. said the first European deal, being marketed now by Commerzbank AG, may call into question SME issues as true covered bonds if it fails to qualify for indexes benchmarking performance....(here)