In her acclaimed 1993 book "Denying the Holocaust," Deborah Lipstadt called putative WWII historian David Irving "one of the most dangerous spokespersons for Holocaust denial." A prolific author of books on Nazi Germany who has claimed that more people died in Ted Kennedy's car at Chappaquiddick than in the gas chambers at Auschwitz, Irving responded by filing a libel lawsuit in the United Kingdom -- where the burden of proof lies on the defendant, not on the plaintiff. At stake were not only the reputations of two historians but the record of history itself.