Since reporting the story, we heard from two sources, who asked to remain anonymous, that it wasn't Adler drumming on the album. (When we asked who did drum on the album, they never responded!).
Anyway, ABC News Radio figured why not ask the man himself? When asked if that was him behind the kit on "The Negative One," Adler commented:
“Right now I think silence is golden. Right now I don’t think those guys need me, or need me talking about it. You know, I listened to it and I thought it sounded a little bit like me, too. At the moment, I just don’t recall doing it. I’m getting texts and emails and phone calls about it. [But] for the moment, I don’t know anything about it.”
I admire Adler for remaining coy and playing into the game of suspense that Slipknot are putting their fans through.