Vanessa Blum writes for The Recorder, an American Lawyer affiliate.

If Mayer Brown gets its way, it could be savoring a sweet win for yogurt maker Chobani.

L.A. partner Dale Giali contends his opposing counsel in a food labeling class action should get the boot because they consulted with an expert previously retained by the defense. Plaintiffs lawyers, he says, now find themselves in a "legally impermissible position."

It’s one of dozens of food labeling cases brought by the same consortium of plaintiffs counsel pending in the Northern District of California but the only one where they are facing disqualification.

"Chobani seeks disqualification, not to gain a tactical advantage," Giali wrote in a March court filing, "but to ensure a level playing field, stop the ongoing harm plaintiffs’ counsel caused by their own willful and wrongful conduct, and protect the integrity of the judicial system."

A motion to disqualify counsel is a nuclear option. It can stop a case in its tracks, particularly in a class action where individual plaintiffs are ill-equipped to simply hire new lawyers. The tussle in the Chobani case before U.S. District Judge Lucy Koh in San Jose raises questions about the standard for ejecting attorneys when they court an expert witness working for the other side.

To be fair, that is closer to Chobani’s version of events; plaintiffs attorneys insist they did not know a former U.S. Food and Drug Administration official they hired to consult on a swath of litigation had previously advised Chobani’s defense team. Since no confidential information was exchanged, there is no grounds for disqualification, plaintiffs contend.

"Chobani seeks to have this court not only disqualify an expert, an act which the Ninth Circuit has found to be a ‘drastic measure,’ but to disqualify counsel as well," plaintiffs attorneys Pierce Gore of Pratt & Associates in San Jose and Robert Clifford of Clifford Law Offices in Chicago wrote in a response brief. "Motions to disqualify opposing counsel must be closely scrutinized because of a significant possibility that the motion is brought for tactical reasons."

Between the two sides, six legal ethics experts have a weighed in either to support the lawyers’ disqualification or to oppose it. Gore, lead local counsel for the plaintiffs consortium, declined comment, as did Giali, Chobani’s lead lawyer.

In Kane v. Chobani, plaintiffs accuse Chobani of misleading customers with "all natural" labeling and by listing "evaporated cane juice" as an ingredient rather than sugar. Plaintiffs lawyers are seeking monetary damages and an injunction blocking sales and advertising of the yogurt as currently labeled.

The case is part of a string of similar class actions filed in the Northern District by Gore’s group, which is led nationally by Clifford and Mississippi plaintiffs lawyer Don Barrett, a veteran of litigation against Big Tobacco. The district has become known as "food court" for the prevalence of such litigation, and defense lawyers have had a hard time knocking out the labeling claims.

A hearing on Chobani’s motion to disqualify counsel is set for July and the parties’ dueling briefs present the following timeline: In May 2012, within days of being sued, Chobani lawyers contacted food labeling expert Elizabeth Campbell of EAS Consulting Group in Alexandria, Va. The defense team continued to consult with Campbell in "repeated, detailed, and confidential strategy sessions" until January, according to Chobani’s motion.

Plaintiffs lawyers say they hired EAS Consulting and Campbell to work on their litigation team in October. EAS chairman Edward Steele informed the team that EAS would be unable to work on the Chobani case but did not provide details, explaining only that EAS would not perform work against a former or current client.

"Campbell never disclosed that she had been engaged by Chobani on any matter and never disclosed that she was serving in any capacity in this case," Gore and Clifford wrote in their response brief.

Two plaintiffs-side lawyers met in October with Campbell and Steele and discussed the group’s litigation. "They never asked for or received any information on how food manufacturers might defend these lawsuits," Gore and Clifford wrote. "Nothing was discussed at all regarding Chobani, the company or this case."

Following the October meeting, plaintiffs claim all discussions with Campbell pertained to a suit against Del Monte Foods and that contact ended in late January after defense lawyers Giali and Mayer Brown partner Michael Resch notified Gore of the potential conflict. On Feb. 1 EAS terminated its agreement with plaintiffs.

Giali insists opposing counsel did not meet their obligation to probe the possible conflict with Chobani. That plaintiffs did not specifically discuss the Chobani case with Campbell is irrelevant, because the food cases involve very similar legal theories, Giali argues.

"The notion that Ms. Campbell never technically worked for plaintiffs on this case is a legal construct," he wrote. "She certainly worked for plaintiffs on the misbranding theories they are alleging in this case."

Gore and Clifford see the issue differently and have four legal experts backing them up.

"It is hard to imagine what harm, if any, Chobani would suffer if the case were simply to go forward," wrote Joshua Davis, director for the Center for Law and Ethics at the University of San Francisco. "The advice EAS gave plaintiffs counsel seems quite straightforward and unrelated to any confidences Chobani might have shared with EAS."

Drinker Biddle & Reath partner Lawrence Fox, who lectures on legal ethics at Yale Law School, submitted a declaration accusing defense lawyers of a "shocking attempt to secure draconian relief" and opined that disqualification would be "the death of the action." It was Chobani’s lawyers, Fox asserted, who violated rules of civil procedure by intimidating Campbell into ending her contract with plaintiffs counsel.

Plaintiffs’ views are also buttressed with declarations from Fordham University law professor Bruce Green and former State Bar prosecutor Ellen Pansky. Green said Chobani’s logic would bar experts for the defense in a single lawsuit from working as plaintiffs experts in other cases based on similar theories, a result he called economically unfair.

Chobani has its own experts: UC-Hastings law professor Geoffrey Hazard Jr. and Ellen Peck, a former State Bar judge and past chair of its Committee on Professional Responsibility and Conduct.

Hazard said failing to ascertain the nature of Campbell’s conflict in the Chobani case amounted to "a flagrant violation" by plaintiffs counsel of recognized standards of professional conduct. Relying on assurances from EAS, which had a financial motive to downplay the conflict, was not enough, Hazard stated in a four-page declaration.

Peck concurred that disqualification of counsel "would be more than justified in these circumstances."

Chobani’s lawyers cite the 1994 California Court of Appeal case Shadow Traffic Network v. Superior Court, which established a rebuttable presumption that an expert witness who switches sides has shared their inside knowledge.

In that case, the court affirmed the disqualification of Latham & Watkins, after Latham hired an expert who previously attended a one-hour meeting with the firm’s opposing counsel. Plaintiffs say Shadow Traffic‘s presumption should not be applied because nothing prevents Chobani’s lawyers from questioning Campbell to find out whether she disclosed confidential information.

Chobani insists it doesn’t have that burden. The company’s legal team conveyed sensitive information to EAS with the expectation of confidentiality. Under Shadow Traffic, Chobani does not have to prove Campbell in turn transmitted her knowledge to plaintiffs lawyers, Giali argues.

"They must be disqualified," he stated in Chobani’s motion, "and they have absolutely no one to blame but themselves."