Have you considered suing the third party that made a false accusation? It seems that they’ve caused suffering and irreparable long term harm. This sounds like something that may have a standing. Perhaps you can sue them and either get some material compensation (if they are well to do) put them through a few rounds of trials in another state or something (if they are poor, this will be a good punishment in itself).
[Not a lawyer, this maybe a bad idea. But what you’re describing should have consequences for the party that had caused harm.]
Also not a lawyer, but there is a significant motivation for protection when an incorrect accusation is made in good faith, because a lot of correct reports of child abuse are based on circumstantial evidence and suspicion - so you would need very clear strong evidence that the reporter knew the information was false and was intentionally misleading CPS, or you’d be thrown out of court immediately. In some places you wouldn’t even be given the identity of the reporter.
But on the same note, I would also consider suing child services for failing to act according to their own principles and mainly for ignoring evidence.
Yes, it seems that there’s nothing that opposes child services to protect parents and children from a zealous and righteous institution.
But we do have an example of another righteous institution misbehaving - churches are now paying back for years of children abuse (Catholic priests abusing children). I don’t see why cases like the one above that forcefully separating children can’t go the same way.
It doesn’t really matter that “most reports are good faith”. Most priests are also good faith…
[Not a lawyer, this maybe a bad idea. But what you’re describing should have consequences for the party that had caused harm.]