If they're not guilty they might as well be. Sorry.
Abandoning toddlers should be a prosecutable offense, and that goes for all the people who did it and had their toddlers survive.
If there is a reason these resorts offer this "service" I suppose it's because they think otherwise the parents would leave their kids all alone anyway and don't want the negative publicity that would follow if and when some of the kids end up dead or injured.
Regarding point a), if they were covering up for something, the abduction was their alibi, so of course they would have to have admitted leaving the children alone. It wouldn't have gone down half as well to say that we were here watching our kids and oops, one of them is gone. Maybe the unlocked door was an alibi too, to explain how the perp got in.
I was meaning that one of the people who said it was a cover-up claimed she died accidently, but it was covered up as an abduction to hide the fact they had left the children. But obviously there is no point staging a cover-up if you are going to admit something straight away.
But you could also say a parent who lets their child walk alone to school is guilty if the child is abducted. the parent let their child walk alone fully aware that if someone tried to abduct them the child could not defend themselves. Should Etan Patz's parents have been prosecuted? Should the parents of Holly Wells and jessica chapman be prosecuted for letting them walk through a village on their own in the early evening? What about the mother of natasha in austria, she allowed her daughter to wal to school with just another ten year old, and her daughter was kidnapped when she would not have been if an adult was there?