In its motion to have Cockburn removed, Google said he ignored the fact that it tried to negotiate a Java license with Sun several years ago. There is "no need to speculate" about the cost of a license because Google and Sun "actually engaged in negotiations regarding a license to the entirety of Java," Google's lawyers wrote.

Alsup took that as a sign that Google may have knowingly infringed Oracle's patents, and asked it to explain itself at Thursday's hearing.

"[I]t appears possible that early on Google recognized that it would infringe patents protecting at least part of Java, entered into negotiations with Sun to obtain a license for use in Android, then abandoned the negotiations as too expensive, and pushed home with Android without any license at all," he wrote last week. "How accurate is this scenario? Does Google acknowledge that Android infringes at least some of the claims if valid?"

Google is likely to respond with one of two arguments, saidDavid Mixon, a patent lawyer with Bradley Arant Boult Cummings who has been following the case. It could say it never expected to infringe Sun's patents and tried to negotiate the license merely as a precaution, to avoid potential litigation costs down the road. Or it could say that having failed to negotiate a license, Google changed its plans and designed Android in a way that it does not infringe the patents.

Either way, it's a serious question for Google. Damages can be automatically tripled if a defendant is found guilty of willful infringement. "The question of willful conduct is a serious risk factor for Google here," said Florian Mueller, author of the .