Where was there a septic tank? I don't think JP had anything to do with this. The stories involving his connections to drugs were rumors. Today, if those rumors were true, he would be out of a job so fast and if convicted could serve jail time. Can't see JP involved here. Somebody would have had to have seen him leaving with Roger, doing something to him, and than JP returning to school to teach. Too fast of a timeframe IMO.
Somebody saw Roger leaving the school that morning and possibly more. Much more.
Satch