Bill Cosby’s civil trial over allegations that he sexually assaulted a teenage girl at the Playboy mansion nearly 50 years ago.Plaintiff Judy Huth said in a recent court filing that she now believes the assault happened in 1975 when she was 16, not in 1974 when she was 15 as she had long alleged, spurring cries of foul and a request to dismiss the case from Cosby’s attorneys, who said the change has upended their defense on the eve of trial.“It's not fair,” Cosby's lawyer Jennifer Bonjean said outside court. “It's called trial by ambush.”Los Angeles County Superior Court Judge Craig Karlan gave no indication he planned to throw out the 8-year-old case just before a trial that he is determined to have start as scheduled on Monday, and forged ahead in preparations.Cosby, 85, will not attend any of it, his attorneys said.