Yes, they are that cruel. Just think of what you already know. They failed to report a statutory rape (at the very least, if not child sexual abuse and rape!). Shunning and banishment is very possible.
And this, is a criminal offense in Canada (not reporting):
(apparently force himself on an underage girl but oddly the police were never involved)
Other jurisdictions differ, but the JWS receives NO clerical protection under the law. They *must* report, like any other citizen (repeat, in Canada).