I think the reason some people were sceptical of children's services is
A. Bad stories where they have screwed up, bias
B. There was no info released as to why they need to be caught. We know he's a sex offended but due to his age/lapse of time. If we were told he/they did XYZ I don't think anyone would have a hot if empathy. When they first went missing it was so bizarre, all we knew was the car was in fire and they left.
Anyway, I'm not saying I believe this myself. If multiple children are no longer in their care, and they haven't managed to get them back, something isn't right.