This really is only because the SCOTUS will not overturn the fact-finding of a lower court (such as the US District Court that the 2010 evidentiary hearing took place in), only the conclusions based on the fact-finding. A judge found that only one of the recantations was meaningful, and the SCOTUS is not going to change that part of a ruling.
Edit: here's the link that I pulled that last sentence from.
https://www.ajc.com/news/atlanta/judge-rejects-troy-davis-598327.html