Credit rating agencies have faced intense scrutiny over the past few years. Blamed for being too generous in their ratings on complex derivatives that went sour during the financial crisis, they have struggled to repair their reputation.

Yesterday’s Australian court ruling that Standard & Poor’smisled 12 local councils in Australia by awarding a triple A rating to derivatives that collapsed in value less than two years after they were created by ABN Amro’s wholesale banking unit is being hailed as a landmark. It is a ruling that some lawyers argue will lead to copycat litigation against rating agencies in Europe and possibly the US.

But the case – which focuses on the sale of constant proportion debt obligations sold to local councils by an intermediary in 2006 – also raises questions. Why is it that agencies including S&P, Moody’sand Fitch, which have faced controversy over their role in the rating of transactions at the heart of subprime crisis, have not been held to account elsewhere?