SAN FRANCISCO — The lawyer seeking to revive a gender discrimination class action against Twitter Inc. faced pushback Thursday from a California appellate panel about whether the company had a uniform policy regarding the promotion of software engineers.

Jason Lohr of San Francisco's Lohr Ripamonti & Segarich, who originally sued Twitter in 2015 on behalf of one of the company's first female engineers, Tina Huang, told a three-judge panel of the First District Court of Appeal that testimony from the company's own human resources official, as well as hundreds of pages of policy documents, showed that Twitter had a "single promotion process." Lohr indicated that the company managers were the gatekeepers to promotion decisions and that the company had set criteria for who was worthy of promotion—criteria referred to internally as "Impact" and "How." The overall policy, he argued, had a disparate, negative impact on women seeking to move up the ranks at Twitter.

But Presiding Justice Barbara Jones, early in Lohr's argument, pointed out that the trial judge who denied the request to certify a class in the case had found that Twitter's stated criteria were "subjective." Jones pointed out that some of the plaintiff's own witnesses had different experiences: One didn't seek out a promotion. One said she couldn't understand the company's policies.

"The takeaway that your client's own witnesses suggested is there wasn't a uniform policy," Jones said.

Another member of the First District panel, Justice Henry Needham Jr., noted that though the Twitter human resources official had testified that there was an official procedure "not everyone followed it." The path to promotion, Needham said, seemed to be a "moving target" and "changed depending on who it was and what time it was."

Huang, who joined the company in 2009 as one of its first female software engineers, is seeking to certify a class of 135 current and former women employees who held similar positions. San Francisco Superior Court Judge Mary Wiss, who last year denied class certification in the case, pointed to the U.S. Supreme Court's 2011 decision Walmart Stores v. Dukes, which found that a nationwide class of women employees at the retail store was inappropriate since promotion and pay decisions were made by local managers without a common mandate from the company. Disparate impact alone, Wiss found, was not enough to allow the gender discrimination class against Twitter to proceed on a classwide basis.

Prior to Thursday's hearing, the First District Court of Appeal asked the parties to address whether Wiss had erred in finding that Huang had failed to establish commonality and whether Twitter had "a uniform system of selecting and assessing candidates for promotion during the class period."

Representing Twitter on Thursday, Orrick, Herrington & Sutcliffe's Eric Shumsky said that the plaintiff could "not remotely show" that Wiss committed a "manifest abuse of discretion," the standard to meet for the Court of Appeal to overturn the trial judge's decision. Shumsky argued that with more than 100 managers making subjective judgments there was no "uniform policy consistently applied." Shumsky also said that even if the court did accept the plaintiff's argument that Twitter had a uniform policy, Wiss had noted in her denial of class certification that the plaintiff hadn't put forward any common method to show that the policy was the cause of a disparate impact on promotions for women.

"It's not just that they have no common way of proving cause," Shumsky said. "It's that they say there's literally no way to prove cause."

On rebuttal, Lohr said that the company had repeatedly in 2013, 2014 and 2015 restated managers' central role in designating candidates for promotion. "If we're to believe Twitter that managers basically have this very wide discretion to do whatever they want, it begs the question why the company would go to the trouble" to create hundreds of pages of policy and a complex matrix of skills for certain software engineering positions.

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