In the case of Wayne Estelle, Warden v. Mark Owen McGuire (1991), the United States Supreme Court addressed whether a federal court could review a state prisoner's claim that his conviction was obtained through use of an involuntary confession if he had not presented this claim in state court due to procedural default. The petitioner, Mark Owen McGuire, argued that his confession was coerced and therefore should have been excluded from evidence at trial. However, because he failed to raise this issue during his appeal process in California courts as required by state law, it constituted a procedural default which typically bars federal habeas corpus relief unless there is cause for the default and actual prejudice resulting from the alleged violation. The Supreme Court held that even though McGuire did not comply with California’s procedure requiring him to object at trial or on direct appeal about coercion claims related to confessions used against him in criminal proceedings; under certain circumstances such as where fundamental fairness might be undermined or miscarriage of justice would result - Federal Habeas Corpus relief may still be available despite non-compliance with State procedures.

In the dissenting opinion for Wayne Estelle, Warden v. Mark Owen McGuire, Justice Scalia disagreed with the majority's decision to grant habeighas corpus relief to McGuire based on ineffective assistance of counsel during his trial. He argued that there was no reasonable probability that the outcome would have been different if not for alleged errors by defense counsel. The evidence against McGuire was overwhelming and included eyewitness testimony as well as physical evidence linking him to the crime scene. Furthermore, he contended that even if some aspects of defense strategy could be criticized in hindsight, they did not amount to constitutionally deficient performance under Strickland v. Washington standard which requires showing both incompetent representation and prejudice resulting from it.