It's hard to believe anyone was clean, but he is at least one of the few from the 2000's that haven't been directly implicated by someone... But he did ride with both Riis and Saiz, although both had trouble with training methods (saying something like that he wanted to do it his one way).
Anyway, if he was clean, you gotta feel sorry for the guy... His best friend was Jimenez by the way, and he is married to Jimenez' sister right? I don't know if that could have been a deterrent, seeing as how that went.