Lynn Tilton, the owner of the private equity firm Patriarch Partners, has been called a diva, a publicity hound, and—somewhat more charitably—an "Ayn Rand heroine in six-inch heels who has men stay for the night, then eats them for breakfast." Thanks to her lawyers at Brune & Richard, Tilton can now add "effective witness" to the list. She can also breathe easier, knowing that MBIA Inc.’s $100 million breach of contract lawsuit against her has finally come to a close.

In a hefty 156-page ruling issued on Monday, U.S. District Judge Robert Sweet in Manhattan ruled that Patriarch didn’t violate an agreement to help MBIA repair collateralized debt obligations (CDOs) it insured. Sweet’s ruling follows a bench trial that pitted a Brune & Richard team led by Hillary Richard against MBIA’s lawyers at Bingham McCutchen.

Back in 2002, long before the financial crisis, MBIA realized that seven CDOs it had agreed to insure were performing poorly. If the CDOs didn’t start raising money, MBIA estimated that it would have to pay between $91 million and $198 million out of its own pocket. The following year MBIA hired Tilton’s company, Patriarch, to help remediate the CDOs. To raise money for MBIA, Patriarch did what it does best: It bought up loans issued by banks to distressed companies, bundled the loans into a complex collateralized loan obligations (CLOs), and issued notes to investors.

Tilton’s strong track record with CLOs—not to mention her penchant for fur and diamonds—has made her a standout player in the finance world. But the CLO she structured for MBIA didn’t live up to expectations. According to MBIA, that’s because Tilton fell down on a contractual duty to secure favorable ratings for notes issued by the CLO. MBIA sued Patriarch in 2009, seeking reimbursement of the money it paid out in insurance premiums. According to Patriarch’s lawyers at Brune & Richard, MBIA was seeking damages pegged at $100 million.

Instead, Sweet sent MBIA home empty-handed on Monday. The 90-year-old judge wrote that Patriarch’s contractual duty was simply to make a reasonable effort to have notes rated as soon as reasonably practical. MBIA produced "no evidence" establishing that Patriarch didn’t meet that duty, he wrote.

The judge also seemed won over by Tilton’s testimony in the case. "She was vigorous, authoritative, informed and almost entirely supported by documentary evidence," he ruled. "Tilton’s recollection of events was clear and unshaken. She was an effective witness and in the main entirely credible."

"It’s really something to be able to impress . . . a judge who has been on the bench as long as Judge Sweet has," Hillary Richard of Brune & Richard told us. "Obviously, we’re incredibly pleased."

Jeffrey Smith of Bingham referred us to an MBIA spokesman, who said the company was disappointed by the ruling and considering its options.