If Paterno thought McQueary wasn't a credible witness and was motivated by jealousy or other malicious intentions - why was he given a job for the next decade plus?
Would you want someone prone to making up wild accusations around your organization for the next decade?
The mother who was concerned about her son showering with Sandusky was motivated by jealousy?
With regard to your last question, there are such things as jealous stage-moms.
Anyways, discussing it in the abstract is as far as I want to go. Regardless of whether or not Sandusky is a true sociopath, he's a real monster responsible for some horrifying crimes. As I said, we all know how it turned out.