Close, but no cigar.
The Second Circuit agreed with the District Court that counsel for Cox, a criminal defendant in a murder case, was ineffective in failing to object to a patently unconstitutional jury instruction on intent, where intent was the primary issue in the case, and that counsel's ineffectiveness prejudiced Cox. It also agreed that the state courts' denial of Cox's appeal "involved an unreasonable application of clearly established Federal law, as determined by the Supreme Court." However, it vacated the decision of the District Court, granting Cox a writ of habeas corpus because the District Court had not affored Cox's counsel an opportunity to explain his deficient performance, as required by the case law. While the Court doubted that Cox's counsel could "offer an explanation to defeat the conclusion that his performance was a result of ignorance, inattention or ineptitude," it nevertheless remanded the case to the District Court for further proceedings.
The decision in Cox v. Donnelly
can be found here