Absolutely, the Basel Accord is the root of our current financial turmoil
Plender refers to how through the minimum capital requirement calculations imposed a regulated arbitrage opportunity was created that forced and stimulated the creation of a parallel financial world that ended up much more difficult to comprehend. To this we would also add the fact that when the regulators then appointed the credit rating agencies as their frontline commissars, then really they set the table for the systemic risks to build up.
Also when Plender asks “whether top executives, let alone non-executives, can really understand the risks being run in such large, complex [financial] institutions”, worrisome as that might be, much worse is having to ask whether our bank regulators really know what they are up to.