Tony Mauro is Supreme Court correspondent for The National Law Journal, an American Lawyer affiliate. This article originally appeared in the NLJ’s Supreme Court Insider.

Even with momentous issues like same-sex marriage swirling around them, U.S. Supreme Court justices on Monday seemed to relish sinking their teeth into a case asking them to define when a Fair Labor Standards Act lawsuit can be deemed to be moot.

The issue in Genesis HealthCare Corp. v. Symczyk, while technical, drew wide interest from business and consumer groups worried that the court’s resolution of the case will either promote or stifle collective and class litigation.

Laura Symczyk sued the Philadelphia nursing home operator under the FLSA on behalf of herself and fellow nurses, claiming she was routinely underpaid for work she did during her breaks. The company responded by offering her a settlement that would compensate her for the unpaid work.

When Symczyk did not respond to the offer, the company sought and won dismissal of the suit as moot for lack of jurisdiction under Rule 68 of the Federal Rules of Civil Procedure. But the U.S. Court of Appeals for the Third Circuit reversed, expressing concern that finding the case moot in Symczyk’s individual case would “frustrate” the intent of the labor law to allow one worker to litigate on behalf of a group of employees.

“If employers can shut down the legitimate legal grievances of many merely by offering to buy off one employee, it will harm both the workforce and the work the employees are conducting,” said Marcia Greenberger, co-president of the National Women’s Law Center, which filed a brief in the case.

For her part Karen Harned, executive director of the National Federation of Independent Business Small Business Legal Center, who also filed a brief in the case, said a ruling in favor of employees would harm businesses, “especially those in the health-care industry that requires continual patient coverage. Small employers don’t have the financial advantages of much larger firms; diverting their limited resources for unnecessary litigation could mean the end of their business and all the jobs they created.”

The court’s more liberal justices seemed united in the view that Symczyk’s claim should not have been declared moot. “The plaintiff’s individual claims have not been fully satisfied,” said Justice Elena Kagan. “She walked away with nothing. She walked away with no judgment, and she walked away with no $7,500. And the question is: How can it possibly be that her individual claim was moot?”

Columbia University Law School professor Ronald Mann, who was representing Genesis, replied that when an employer offers “all of the relief that the person could possibly win in any formal litigation, it has to be the case that the individual’s interest is moot.”

Interestingly, Mann is a former law clerk to the late Justice Lewis Powell Jr., who made the same point in dissents in the two leading precedents in this area from 1980: U.S. Parole Commission v. Geraghty, and Deposit Guaranty National Bank v. Roper.

Former acting solicitor general Neal Katyal, who argued on behalf of Symczyk, got skeptical questioning from court conservatives.

“Why are you arguing so much?” said Chief Justice John Roberts Jr. A favorable judgment in Symczyk’s case, if she had accepted it, would serve as precedent for future individual cases, Roberts said.

In response, Katyal, now with Hogan Lovells, invoked the late Justice William Rehnquist, whom Roberts worked for as a clerk, as asserting that an individual case is not always “just about the individual plaintiff.” Rehnquist took that stance in a concurrence in the Roper case, which was decided the term before Roberts worked for him.

At the beginning of his argument, Katyal used another argument that should be familiar to Roberts. Roberts asked whether the lawyers for Symczyk had waived a key constitutional argument in the case by not mentioning it in the brief in opposition filed at an earlier stage of the case.

Katyal, who was retained by Symczyk after that brief was filed, told Roberts, “It was a mistake on our part.” But Katyal argued that the issue could still be considered. He offered several reasons for that assertion during oral argument and in a footnote in his merits brief.

In 1997, Roberts made similar arguments in defending a similar omission. The case was Adams v. Robertson, and Roberts at the time was working for the same firm where Katyal now is co-head of the appellate practice.