According to a Justice Department official, who spoke on the condition of anonymity, the department decided to release the e-mails despite the internal belief that the messages were irrelevant.

"As a general matter we believe that the e-mails are not material to the case. We came across the e-mails during our investigation and do not think they are material but thought we would err on the side of caution and provide copies to Microsoft and the courts," the official said.

In addition to the e-mail from Lessig to the Netscape executive, the Department released two e-mails from technical and legal personnel at Netscape to Lessig.

The Mere Appearance of Bias

The mere appearance of bias must be avoided in any arbitration, said Harry Besunder, a member of the New York State Bar Association's Committee on Professional Responsibility.

"When you're talking about any person who acts as an arbitrator...the parties have to be assured that they are totally unbiased and that their internal prejudice will not affect their ultimate determination," he said.

Leslie W. Abramson, a professor at the University of Louisville and the author of Judicial Disqualification, applied this doctrine to the Lessig case, saying Lessig's impartiality "might reasonably be questioned."

"The extent to which personal bias is a disqualifying factor is the function of what judges say," he said.

"If he gave a [general] speech or wrote an article I don't see any problem," Abramson notes. "It sounds to me that he has gone beyond any general comments."

The Justice Department's rebuttal to Microsoft's petition, written by Assistant Attorney General Joel I. Klein, counters that the e-mails do not create "any reasonable indication that Professor Lessig is biased against Microsoft."

"[Microsoft's] assertions are unfounded and overblown and depend largely on assumptions and conjecture," it read.