Just what "more" do you want?
Third party confirmation.
Or more precisely, just what in the hell would you expect them to let you see?
I don't expect them to let me see anything. I also don't expect them to announce it if some hacker completely fucked over Steam. It's always going to be some "third-party site" that's to blame.
I realize they don't have any obligation to answer my doubts. But their history doesn't give me any reason to give them the benefit of the doubt. So I'm not going to accept their explanation unless it's confirmed by someone unaffiliated with them (law enforcement, and suchforth).