What are the elements of judicial estoppel?

However, even if all elements are established, judicial estoppel is not invariably applied. (People v. Castillo (2010) 49 Cal.4th 145, 156.) "Because of its harsh consequences, the doctrine should be applied with caution and limited to egregious circumstances." (Gottlieb v. Kest, supra, 141 Cal.App.4th at p. 132.) "'It is an "'extraordinary remed[y] to be invoked when a party's inconsistent behavior will otherwise result in a miscarriage of justice.'"' [Citation.]" (Id. at pp. 130-131.)