In Kulchar v. Kulchar (1969) 1 Cal.3d 467, the Supreme Court explained extrinsic mistake, emphasizing its relationship to a fair hearing. The court described extrinsic mistake as "'excusable neglect of the party to appear and present his claim or defense. If such neglect results in an unjust judgment, without a fair adversary hearing, the basis for equitable relief is present, and is often called "extrinsic mistake."'" (Kulchar, supra, 1 Cal.3d at p. 471, ) The court explained further: "Relief is denied, however, if a party has been given notice of an action and has not been prevented from participating therein. He has had an opportunity to present his case to the court and protect himself from mistake or from any fraud attempted by his adversary. . . . 'A rule which would permit the re-opening of cases previously decided because of error or ignorance during the progress of the trial would in a large measure vitiate the effects of the rules of res judicata.'" (Kulchar, supra, 1 Cal.3d at p. 472.)