Whether the FM & FF are guilty of doing anything to William or not, they were today charged with both assaulting an 11 year old child.
No matter how you cut it, they look like pretty terrible people if the alleged assault is found to be true.
And IMO, to add to that, homicide detectives are not going to take out AVO's / Charge people in an unrelated assault case (especially given their wealth, legal representation and perceived 'victim status' for losing William) unless they have something pretty damn good.