Should a certificate of appealability have issued, where the suppressed evidence, considered cumulatively, would have placed a burden on the Commonwealth to disprove heat of passion and would have provided threshold support for trial counsel's voluntary manslaughter instruction request?

At Mr. VanDivner's post-conviction hearing, it was determined that three pieces of evidence had been suppressed by the Commonwealth prior to his trial. This evidence was material support for a voluntary manslaughter defense. If competent trial counsel had been provided this evidence, she would have undertaken a more thorough investigation that would have uncovered additional information supporting a voluntary manslaughter defense theory. Counsel would then have properly presented this theory at trial, and the burden would have necessarily shifted to the Commonwealth to disprove that Mr. VanDivner acted in the heat of passion. This evidence would have also supported trial counsel's on-the-record request for a voluntary manslaughter instruction. These eventualities were not considered by the District Court for the Western District of Pennsylvania in denying Mr. VanDivner's habeas petition nor by the United States Court of Appeals for the Third Circuit in denying his request for a certificate of appealability. The question presented is: Should a certificate of appealability have issued, where the suppressed evidence, considered cumulatively, would have placed a burden on the Commonwealth to disprove heat of passion and would have provided threshold support for trial counsel's voluntary manslaughter instruction request?