In the bankruptcy cases that followed, claims of fraudulent transfer were sometimes brought, most prominently in the bankruptcy of the Tribune Company, which had been bought by Sam Zell in an $8.2 billion buyout.

Such claims have come as a bombshell to the former shareholders of these companies. They thought the deal was long done. The money was paid out, and shareholders reinvested it in new stocks or perhaps a new kitchen. But like a ghost from the past, a bankruptcy trustee knocks on the door years later, demanding repayment.

Even if the trustee does not succeed, the shareholders face legal costs to try and prevent repayment. In the Lyondell case, the trustee sued shareholders who received more than $100,000. He then included everyone, down to a grandparent in Florida who owned 10 shares. And in a lawsuit you need to hire a lawyer.

So far, some of the larger shareholders have been paying for the defense. And the old Lyondell shareholders have had success in fighting off the bankruptcy trustee’s charge. The trustee initially brought two claims. The first was a claim for constructive fraudulent transfer; the second for actual fraudulent conveyance. The difference between the two is intent. The first is the easier to bring since it allows the court to look at the surrounding circumstances, while an actual fraudulent conveyance needs a finding that the sellers — here Lyondell — had “actual intent to hinder, delay or defraud” creditors, a high standard.

In a decision involving the Tribune case, the United States Court of Appeals for the Second Circuit threw out the constructive fraudulent conveyance claims on a technicality, holding that those claims were barred by another section of the bankruptcy code that prohibited suits against security holders. The case applied to the Lyondell case and other leveraged buyouts equally, at least those litigated in New York.

This left Lyondell’s former shareholders with hope that the actual fraudulent intent claim could be thrown out. Success was had in the bankruptcy court, but bankruptcy court rulings are subject to review in the district court, and that is where the Lyondell shareholders met Judge Denise L. Cote.

The plaintiffs claimed that there was actual intent here as a result of the actions of Lyondell’s chief executive at the time, Dan F. Smith. In the hasty negotiations of the Basell deal that unfolded in a week, Mr. Smith was accused of updating projections that the plaintiffs said were overly optimistic.