Call it a case of pro bono gone awry.

When Manhattan federal district judge Colleen McMahon issued an order approving a proposed settlement between a class of roughly 26,000 tenants—represented by a Jenner & Block team led by litigation partner Richard Levy—and New York–based property manager the Pinnacle Group on June 6, 2012 [PDF], the end of a six-plus-year legal battle appeared at hand.

The proposed settlement did not compel Pinnacle—which the plaintiffs claimed had harassed and imposed illegal rent increases on rent-controlled and rent-stabilized tenants in some of its nearly 15,000 New York apartments—to admit wrongdoing. The company did, however, agree to a lease audit and two-year injunction period during which it would be monitored to ensure adherence to terms of the settlement that called for class members to be compensated for past rent overcharges; unnecessary billings and fees stemming from eviction proceedings; and Pinnacle’s alleged harassment and violation of the aggrieved tenants’ rights. Pinnacle and its owner, Joel Wiener, also agreed to pay $2.5 million to cover the legal fees and counseling costs of specific legal and tenant-rights groups chosen to oversee the settlement’s enforcement.

Though McMahon called the settlement “fair, reasonable, and adequate,” its terms—and how they were reached—upset some members of the class. As a result, tenants who for years fought alongside the Levy-led team are now fighting to scuttle the agreement Jenner’s lawyers reached on their behalf. Among their complaints: that tenants did not have enough input in the proposed settlement; that the agreement does not clearly establish which tenants are entitled to compensation; that Pinnacle is only being held responsible for overcharge claims dating to 2004; that class members are being offered less in damages than similar claims brought in state court typically yield; that Pinnacle—rather than the tenants—got to pick which tenant groups will control the settlement funds; and that Jenner does not deserve the $1.25 million in fees and $200,000 it is slated to collect in connection with the settlement.

The objections are detailed in a pair of appeals filed with the U.S. Court of Appeals for the Second Circuit by two separate groups of class members seeking to upend the settlement—one made up of the five class representatives, the other composed of three other objectors—in July and consolidated in October. While appellate briefs in the case have now been filed, oral arguments have not yet been scheduled. In the meantime, Levy says, the objectors’ protests are undermining the enforcement of what he believes is a fair settlement.

“All these 26,000 people are simply being deprived not only of the dollar remedies but of the benefits of the injunction and so forth,” he says, adding that it is “pretty rare” in a class action for all of the class representatives to oppose a proposed settlement. (Matthew Chachere, an attorney representing some of the tenants appealing the settlement, agrees and says he could not find a record of it ever happening in the Second Circuit.)

Now in its seventh year, the Pinnacle case—and the ongoing dispute between attorney and client—appears to be something of an oddity in the annals of pro bono. “I think this is a relatively rare occurrence,” says Pro Bono Institute president and CEO Esther Lardent, while noting that class actions involving landlord-tenant and employment-related disputes are more likely than other kinds of cases to see plaintiffs chafing at settlement terms. Julie Carpenter, a Washington, D.C.–based Jenner litigation partner who serves as one of four cochairs of the firm’s pro bono committee, says she is unaware of any similar cases involving Jenner. “My sense is this is kind of uncharted territory,” says Carpenter, adding that she is most familiar with the D.C.–based matters the firm takes on.