Balance sheet ballet” is not a dance known to many outside the financial world. A manoeuvre popular in the 1990s, it involved banks with closures different from financial years engaging in fancy footwork, moving around loans between each other to flatter their figures.

Tactics have become more sophisticated in the past decade as banks have created an explosion of cheap credit, leading to a ballooning of their balance sheets. The idea was not limited to banks: Enron, the energy company, also realised the appeal of special vehicles, which it named after characters from Star Wars, as a way to disguise its debt.

Enron’s top brass have gone to prison for committing fraud. No one is suggesting officially, however, that the former boss of Lehman Brothers, Dick Fuld, should be given the same punishment.

The bank funnelled its Repo 105 business through its London operation. The reason seems to have been that not only did it need to use a loophole in US accounting regulations, but also needed to overlay on that British contract law, as the US legal system would not have allowed the documents to be set up in the same way.

For all of the devastating details in the bankruptcy court’s 2,200-page report, Lehman’s directors appear to be off the hook. Mr Fuld was “at least grossly negligent”, Anton Valukas, the lawyer appointed by the New York bankruptcy court, said.

But he concluded that decisions by Lehman’s management did not fall outside the “business judgment rule” — meaning that they may have acted stupidly, but there was no evidence that they were corrupt.

The position of Lehman’s auditor, Ernst & Young, is not as clear. The company is accused by Mr Valukas of failing to raise with Lehman’s board the potential use of short-term loans.

Mr Valukas’s motivation is clear. Appointed by the bankruptcy court, he wants to blame the richest party so that any successful lawsuits win the largest possible amount for creditors to the collapsed bank.

Yet this approach could backfire. When lawyers pursued a similar policy over the collapse of Barings Bank in London, the judge said that the bank’s directors also had to take some of the blame.

A US judge might find it hard that Ernst & Young should be blamed while former directors of Lehman escape. But the risk may prompt the company to settle out of court.