petition and which to leave out requires no less competency than determining whether to withdraw a habeas petition. The same competency rule logically extends to both. We therefore hold that, when deciding whether Petitioner possessed the mental competence required under Gates, the district court had to use the procedure and apply the burden of proof that we prescribed in Mason. Not having done so, the court erred. B. Nonetheless, in the circumstances, we need not remand the competency issue. In the usual case, we would reverse an erroneously analyzed competency determination and remand the matter so that the court could apply the correct legal standard to the evidence. See generally San Diego Police Officers’ Ass’n v. San Diego City Emps.’ Ret. Sys., 568 F.3d 725, 741 (9th Cir.2009) (<HOLDING>). Here, however, we need not reverse and remand
recognizing that when reviewing for clear error we usually must reverse if the district court applied incorrect legal standards to reach its findings holding that findings of fact are reviewed for clear error holding that we will not reverse in the absence of prejudice holding the court of appeals was mistaken to engage in factfinding rather than simply reviewing the district courts factual findings for clear error holding that we review for clear error the bankruptcy courts factual findings