Your right, they should have thought about that before accepting a contract with TLC. However, I can only “assume” they believe this was behind him between Josh and the victims. Yet they forgot there was a police report that could have been made public. I find it odd a woman found a note in a book about the situation. Instead of taking it to the police she sends it to Oprah. Yep, if I learned of a crime I will be taking it over to Oprah - NOT!
That fellow congregant, aware that the church had done nothing and that local law enforcement had done nothing, and that the family was going on Oprah to promote themselves, sent a copy of that note to the show's producers.
The producers killed the interview and reported what they found to law enforcement.
Basically, the woman from the congregation found a way to go over the heads of the local Duggar enablers and seek justice.
We don't know what the note says or what the circumstances of the book borrowing were, but it may have been a "message in a bottle" from a victim to an old lady whom she thought could help her.
It would have been behind them if they remained private citizens. Anything that can be considered criminal behavior is never behind you if you are a public personality.
And they knew Oprah knew about it, so why would they think it was behind them when they signed with TLC 2 years later?