See the statement.
In an interview with the website Alternative Nation, Rage Against The Machine drummer Brad Wilk, who played drums on Black Sabbath "13", spoke about the experience:
“It was a dream come true. When I was 14, I would sit in my room with my record player trying to learn Bill Ward’s parts, and Black Sabbath is one of my all-time favorite bands. So, being invited to play drums with them was an incredible experience. During the first week, it was very difficult to deal with the fact that I was in a room with them, making an album with them. They are all great people, I loved being with them, hearing their stories while we made the album. I loved working with Rick Rubin, he’s an amazing producer. I was blessed just to be there doing that, to be part of something incredible. Despite all that, despite it being a wonderful experience for me, I wish Bill Ward had been there in my place.”.