I like your post and I have upped you. Indeed, if the banks told the town councils it was low-risk, then why it bombed? If the bank said it was high risk, then why the town councils still foolishly bought into the high risk investment? It's not their money, but the constituents' money.
Breaking the logic down, if the town councils were told the structured products were low risk and then it bombed totally, then the town councils must sue the banks to get the money back, for it is constituents' money.
However, if the town councils were told it was high risk investments and yet still bought into it and now lost everything, then the town councils owe it to the constituents to make restitution, either monetarily or by way of resignation or some other form of justice, even though resignation is little compensation for the loss.
It should not be simply a quiet wrtie-off for the loss. This is, IMO, unacceptable. Where is the money?