I am amused by TV and Radio commentary that says there is no evidence. It just one persons word against another. Eyewitness testimony is very strong evidence. If Kato had seen OJ kill Nicole and Ron, he'd be in jail today. On TV and Radio, I have heard this referred to as hearsay. Testimony by an eyewitness to the acts in question is not hearsay. Eyewitness testimony by someone that knows you is particularly strong. He had no motive to get Clemens, unless it can be shown that he was pressured to name Clemens. He was pressured to tell the truth, and he feels bad that he turned in a friend, which makes the evidence more compelling. The investigators wanted full and honest disclosure from him. They certainly didn't want him making false accusations. It's not like this is a murder case where the cops are under pressure to arrest and convict someone.
Clemens is 100% guilty. I guess to paraphrase Johnny Cochrane: "Give me one Clemen's fan on the jury and I'll get him off."