Attorneys who once represented Qualcomm Inc. in its ill-fated federal patent case against Broadcom Corp. have asked a judge to pierce their client’s privileged communications.

With the threat of formal sanctions bearing down on them, lawyers at Heller Ehrman and Day Casebeer Madrid & Batchelder � Qualcomm’s former litigation counsel � are asking for a rare exception to privilege so they can explain to the judge how their side failed to produce hundreds of thousands of relevant documents during discovery in the San Diego case.

Qualcomm, citing privilege, has refused to produce any evidence about the discovery error. Magistrate Judge Barbara Major has ordered the attorneys to show cause at an Oct 12 hearing as to why they should not be sanctioned. Now, in advance of the hearing, many of the outside counsel have hired their own lawyers and have been trying to find a way to explain what happened.

Both Heller and Day Casebeer stated in motions (.pdf) filed this week that they had recently asked Qualcomm to lift privilege for this purpose, but couldn’t reach an agreement. Now Heller attorneys are seeking a so-called self-defense exemption from privilege, which they say would let them fully explain, in chambers if necessary, what happened.

“The Heller attorneys believe that they have very compelling exonerating evidence about their role or non-role in the events giving rise to the order to show cause,” their motion stated. “Given the rulings in the proceedings to date and the accompanying publicity, the Heller attorneys seek public vindication, which can only come after a full and complete response to this court’s order to show cause.”

In their motion, Day Casebeer attorneys said they had considered asking for the self-defense exception, but saw it as potentially troublesome to the State Bar. Nonetheless, they are asking the judge to allow them to make use of the exception if it is also granted to Heller attorneys.

Qualcomm counsel William Boggs, a partner with DLA Piper, declined to comment on why the company would not change its stance on privilege. Mark Fabiani, an attorney hired by Day Casebeer to deal with press, also would not comment publicly on the matter, nor would Heller Ehrman Managing Partner Robert Hubbell.

Eric Sinrod, a litigator with Duane Morris not involved with the case, said he hadn’t ever encountered the self-defense exception to privilege in his own work, but said it was important for attorneys to be able to defend themselves against the threat of sanctions.

On the other hand, he said, it’s understandable why a client would closely guard its privilege rights � especially when it is engaged in ongoing litigation in other courts. A client may fear that piercing privilege voluntarily puts its privilege at risk in other cases.

“I could conceive of a situation where a client could be worried that it’s a slippery slope,” he said.

The Heller attorneys’ motion, filed Monday, is offering to explain where exactly the responsibility lay throughout the case for document searches and production, witness interviews and written and oral arguments before the court.

On Tuesday, attorneys for Day Casebeer lawyers filed a motion to join Heller’s. Day Casebeer attorneys had apparently worried that the State Bar might have a problem with an effort to get around state privilege rules.

“Particularly because the order to show cause expressly mentions referral to the California State Bar as a possible sanction,” the motion, written by Joel Zeldin at Shartsis Friese, said, “the responding attorneys concluded that they could not risk whether the State Bar would recognize the self-defense exception in the face of state rules that appear not to.”

Day Casebeer attorneys are asking for the right to use privileged material if Judge Major decides to grant the exception to Heller attorneys.

Day Casebeer attorneys have already prepared written declarations explaining their role in the discovery error, and had planned to file them by Sept. 21. If privilege is pierced, they seek an extra week to file more declarations.

Attorneys under the court’s scrutiny have hired their own lawyers, and some have been switching counsel in recent days. Heller and its six attorneys who had worked on the case first hired San Diego’s Kirby Noonan Lance & Hoge. As of Monday, three of those Heller attorneys, based in Southern California, have switched to representation from San Diego’s Butz Dunn & DeSantis.

Day Casebeer as a firm is being represented by Howard, Rice, Nemerovski, Canady, Falk & Rabkin, and several of its attorneys have hired Shartis Friese. One partner, Craig Casebeer, has hired additional counsel, Chicago-based litigator Richard Prendergast.

Major has set a hearing on the privilege issue for Sept. 28.