I am not insinuating anything.
Not looking at this particular case:
If someone is not prosecuted, or is found 'not guilty', then either they are NOT guilty, or they are but there isn't enough evidence to prove it beyond reasonable doubt. That is what it is.
Not sure what I am supposed to be insinuating 
The system is set up so that guilty people go free rather than innocent people get convicted. It isn't perfect, of course, and miscarriages of justice happen. But the principle is that when someone's facing prison and a criminal record, they have the benefit of any possible doubt.
In a civil court that isn't the case. A civil court looks at what is most likely. Which is why a family court might conclude that a child has probably been abused, and act to prevent further abuse, even though there is no criminal conviction.
WRT this particular case:
I have no info on this case other than what the birth parents and their lawyers have said.
What they say may be 100% accurate, it may not. I have no idea - and neither does anyone else on this thread, despite the certainty some people seem to have...