I have the 28th Virginia Infantry Virginia regimental history book. Its says that he stayed at the Hospital until May 28 1863 from when he was wounded at 2nd Manassas. In the roster info it says that he was MIA on July 3rd. But as you have found it also says that he was reported killed. I would say that he was buried at Gettysburg. You might be able to visit the CSA cemetery and find him but he may not of been recognised and was buried. But in the book it doesnt say where he is buried. I'm on footnote so I'll look into his service record see if I can find more. If you have anymore ancestors from Virginia in the civil war that you want more info on just send me as much info on them that you can.