Ellen Pao is suing Kleiner Perkins Caufield & Byers over her dismissal from the company, accusing the big-name Silicon Valley venture capital firm of gender discrimination. But the firm's lawyer says gender wasn't an issue.

“There is an entirely different explanation for Ellen Pao’s failure to succeed at Kleiner Perkins," attorney Lynne Hermle said during opening arguments in the Pao-Kleiner trial on Tuesday. "She did not have the necessary skills for the job. She did not come close."

Pao—now the interim CEO of popular online community Reddit—brought the suit against the firm in 2012, and this week, the case went to trial, closely watched by the rest of Silicon Valley. The outcome could go a long way towards defining how people view gender issues in the land of tech innovation.

It's unusual that the case has gone to trial. In these types of delicate situations, parties often push for out-of-court settlements, fearing they may risk damaging their reputations in a very public forum. But according to The New York Times, the rift may run so deep that a deal is all but off the table. And at least for the time being, we have a rare peek into the typically cloaked world of gender discrimination in Silicon Valley.

Early in the day, Pao's attorney, Alan Exelrod, laid out his opening arguments, saying that Kleiner Perkins did not treat Pao like it treated male partners. "Kleiner Perkins used Ellen Pao’s talents for six years,” Exelrod said. "When it came time to choose the next generation of leaders at Kleiner Perkins, Kleiner only chose men." But Hermle, of global law firm Orrick, painted a very different picture.

She began her arguments by running through the 40-plus-year history of Kleiner Perkins, a company that she claims has been very mindful of the tech gender gap and its role in attempting to close it. According to Hermle, the company has given women important jobs at senior levels within the company, and it relies on these women to run critical operations and investments at Kleiner Perkins.

Hermle held a few individuals up as examples: Mary Meeker, a senior partner and longtime executive at Morgan Stanley; Beth Seidenberg, a general manager who joined KPCB around the same time as Pao; Juliet de Baubigny, who has been with the firm since 2001; and Sue Biglieri, who’s served as KPCB’s CFO for 25 years. All of these women, Hermle added, will testify at the trial on behalf of Kleiner Perkins.

She stressed that John Doerr, a central figure in the case as Pao’s boss and longtime mentor (“She was like a surrogate daughter to him,” Hermle said), has been on a mission to increase the number of women in venture capital for many years. According to Hermle, Doerr has personally backed a long list of female executives at the KPCB, and even personally recruited them for high-profile jobs at companies like Amazon and Google, where he serves on the company’s board of directors. Doerr himself recruited Ellen Pao for a job at Kleiner Perkins.

But, Hermle says, Pao was hired not as an investing partner, but to help Doerr personally in a position called "chief of staff." Contrary to the implied duties of the title, Pao was not in charge of supervising a large staff, according to Hermle. The role was largely a technical aide position: that meant writing speeches, helping with the calendar, and many other high-level tasks meant to aid Doerr. In 2010, Pao transitioned into a role as an investing venture capitalist and, because she was not effective at the job, according to Hermle, some Kleiner Perkins partners wanted her to leave after a year. But Doerr fought for Pao to stay on, and she did—but she continued to have conflicts with her colleagues.

According to Hermle's argument, Pao was "supremely insistent on getting credit for things," and she "frequently complained." She complained when there were group tasks that had to be done, insisting that her coworkers were withholding information from her, Hermle says, and she complained that she was working harder than others—harder than both men and women. "At any moment in time, there was someone not getting along with Ellen," Hermle said.

She implored the jury to wait for all the facts and evidence before making a decision in the case. "Ellen Pao fails to meet her burden of proof,” Hermle said, “even though she repeatedly and consistently seeks to twist facts, circumstances and events."