Honestly if there was an accident at night which meant the parent had time to wash but not dry an item, I would have absolutely no problem throwing it in my dryer. If this is an occasional thing then for goodness sake have a heart. If it was a regular thing, maybe confronting the problem after one or two incidents would have cut this short. Sometimes a simple conversation deals with these things amicably rather than going around the houses because a provider is annoyed. I like to be straight and upfront. This mother the OP is talking about should have done this but what is done is done.
Moving forward it should be cut in half or a daycare only blanket should be given to the child, or god forbid just wean him off it. Pick your battles, I have way bigger things that concern me with daycare parents without blowing something like this way out of proportion. I'd really like to know how Kingstonmom got on with this situation.