For weeks, publisher Judith Regan had been in trouble with higher-ups over the debacle of the canceled O.J. Simpson book and TV deal. But her firing swiftly followed a Friday afternoon phone call from her Los Angeles office to a HarperCollins attorney that included comments that were characterized as offensive, two highly placed corporate sources said Saturday. The comments, the precise nature of which was not disclosed, came just before News Corp., the parent company of HarperCollins, held its annual holiday party, an expensive hotel bash in Manhattan attended by more than 4,000 people. Regan's company, Los Angeles-based ReganMedia, is...