What is the case law on habeas relief for a defendant who was found guilty of a lesser crime than his co-defendant in a sexual assault case?

The jury's finding establishes it would not have found him guilty of a lesser crime than Freed or somehow less culpable than Freed because it considered him a major participant. See O'Neal v. McAninch, 513 U.S. at 434 (habeas relief is available only if the record demonstrates the jury's decision was substantially influenced by an error or there is "grave doubt" about whether an error was harmless).