The U.S. Court of Appeals for the Second Circuit overturned the fraud conviction of former Mayer Brown partner Joseph Collins Monday because the Manhattan federal judge who oversaw the end of Collins’s 2009 trial, U.S. District Judge Robert Patterson, didn’t call in defense lawyers when he advised a dissident juror to resume deliberations. The Second Circuit’s 23-page opinion makes for pretty dramatic reading; the juror came to see Patterson with an account of being harassed and threatened for disagreeing with fellow jurors in the course of four days of deliberations. The jury foreman also sent notes to the judge pleading for help in defusing tensions in the jury room. Rarely are we privy to such a vivid, well-documented account of jury-room dynamics.

But if Collins — who was sentenced to a seven-year prison term but has been out on bail pending appeal — is retried, we should get to see an equally vivid fight over whether he engaged in criminal conduct when he decided not to disclose a side agreement between his client, Refco, and the Austrian bank known as Bawag to T.H. Lee, the private equity fund that led a 2004 leveraged buyout of Refco. As Patterson has said, “The evidence which led principally to [Collins's] conviction was his admitted, intentional determination to not disclose the existence of the [side deal].”

That dispute will once again pit Collins against two Weil, Gotshal & Manges partners, who represented T.H. Lee in the LBO and testified at Collins’s first trial that the so-called “upstream” Proceeds Participate Agreement had been hidden from them. This time, however, Collins’s lawyers from Cooley will have some new evidence, uncovered after the first trial, to counter key elements of the Weil testimony.

Cooley argued at Collins’s 2009 criminal trial that the Mayer Brown partner made a judgment call, as a corporate lawyer, about his disclosure obligations, and that his legal reasoning certainly didn’t amount to abetting Refco’s fraud. (Here’s Collins’s 133-page appellate brief, which lays out, in detail, his explanation for not disclosing the Bawag agreement.) But prosecutors argued that Collins covered up the side deal because he was helping Refco defraud Lee and other investors. To support that argument, they relied heavily on testimony from Weil partners Jay Tabor and James Westra, as well as T.H. Lee principal Scott Schoen. All of them said the side agreement with Bawag was critical and Collins effectively hid it from them.

Tabor’s testimony was particularly effective in undercutting Collins’s defense. Collins had asserted that in April 2004, Refco’s CEO told him that he’d reached an agreement with Schoen of T.H. Lee not to disclose so-called “upstream” agreements like the Bawag side deal. Collins said that he, like T.H. Lee, was a victim of the Refco CEO’s deception. But Tabor testified that Collins lied to him before the Mayer Brown partner’s supposed April conversation with the Refco CEO. According to Tabor, he specifically asked Collins about certain categories of documents, which would have included the relevant side deal, in March 2004. Tabor testified that Collins said there weren’t any. “If you believe Jay Tabor,” prosecutors said in their closing argument, “it is over. The defendant is guilty.”