Barclays’ lawyers at Boies Schiller & Flexner made a hefty filing Friday in an effort to convince a judge to dismiss a suit arguing Barclays got a $5 billion sweetheart deal when it purchased Lehman Brothers’ North American assets at the height of the financial crisis. The thousands of pages filed provide a fascinating glimpse into the chaos of September 2008, the kind of glimpse you can only get either when dozens of people are unusually candid or when a lawyer accidentally waives attorney-client privilege and, in the process, opens up a lot of secret stuff to public scrutiny.

The dispute is complicated, and there are dozens of prongs to the Lehman-Barclays transaction, but you can boil the Barclays/Boies Schiller argument down to this: There was no secret agreement to give Barclays a $5 billion windfall in the deal, and Lehman — and its financial advisers as well as its lawyers at Weil, Gotshal & Manges — knew exactly what they were doing when they agreed to the deal in late September 2008, according to court records. (Lawyers on all sides of this conflict declined to comment or didn’t return messages seeking comment.)