They should be wary of him. It is instinct to think that someone who has done it more than once could do it again.
The girls were/are the victims for sure. That is the biggest issue for me. Josh was (and still is) being protected by the parents and even his sisters. The little ones were the most troubling aspect of this. There was nothing sexual about them at all, yet he still did it.
Educate people about the real world and what can happen even in a good family!