A San Francisco Superior Court judge said this afternoon that he didn’t buy arguments by Kleiner Perkins Caufield & Byers that a sex discrimination case against it should be heard in private arbitration. The venture capital firm was sued in May by Ellen Pao, who said she was pressured into sex by a junior partner and then retaliated against when she complained.

Judge Harold Kahn had already told Kleiner that he wasn’t persuaded by its argument that Pao had no legal right to be in open court, but gave the firm a chance to file a revised motion. Today, Kahn told Kleiner “I thought your papers were terrific,” adding, “and I disagree with all of them.”

Here’s a story by the Mercury News about the action in court today.

I wrote about the Pao case in my Bloomberg column last month; Pao had said in her complaint that the top guys at Kleiner didn’t invite women to power dinners with big clients because women would “kill the buzz.” Kleiner denied her allegations.

Kleiner said today that it will appeal the judge’s decision. Companies fight hard to keep sex discrimination and other cases out of the public eye, and nothing serves that goal better than forcing cases into private arbitration. Here’s a story I wrote describing how the public has suffered from 25 years of business forcing litigants into closed-door arbitration hearings.