I don’t think statute of limitations had any bearing on his thought process. If he was willing to pony up $3.5 million to this person to keep quiet that should tell you a lot about how desperate he was to keep this a secret. This wasn’t just sexual assault on a minor but on a minor of the same sex. In the world of right wing conservative Christians that is pretty much the worst thing a person can do. Acknowledging this would cause his entire world to implode. No way would he have voluntarily admitted that to anyone, much less the FBI.