Even an erroneous Fourth Amendment decision in state court does not overcome the Stone v. Powell bar in a § 2254. The question is the fair opportunity to litigate, not the result. Green v. Nagy, 2020 U.S. Dist. LEXIS 16502 (E.D. Mich. Jan. 31, 2020), prior opinion, 2019 U.S. Dist. LEXIS 124063 (E.D. Mich. July 25, 2019):
The relevant inquiry is whether a habeas petitioner had an opportunity to litigate his or her claims, not whether he or she in fact did so or even whether the Fourth Amendment claim was correctly decided. See Wynne v. Renico, 279 F. Supp. 2d 866, 892 (E.D. Mich. 2003); rev’d on other grds 606 F.3d 867 (6th Cir. 2010). Indeed, under Stone, the correctness of a state court’s conclusions regarding a Fourth Amendment claim “is simply irrelevant.” See Brown v. Berghuis, 638 F. Supp. 2d 795, 812 (E.D. Mich. 2009). “The courts that have considered the matter ‘have consistently held that an erroneous determination of a habeas petitioner’s Fourth Amendment claim does not overcome the Stone v.Powell bar.'” Id. (quoting Gilmore v. Marks, 799 F.2d 51, 57 (3rd Cir. 1986)).
This is especially so after AEDPA far more narrow standard of review.