The issue ... and this is THE issue ... is that the elders are not qualified to investigate and decide if a child is still in danger or not.
That one statement "the branch office of Jehovah’s Witnesses will instruct the elders to report the matter IF a minor is still in danger of abuse or there is some other valid reason" leaves a lot open to subjective interpretation. I think that by them putting this is writing, they are opening themselves up to lawsuits later on. This will come back to bite them. They are instructing their elders to make a judgment call that is typically done by trained professionals, i.e. social workers, etc. That makes them liable.
When are they going to understand: STOP INVESTIGATING! CALL THE AUTHORITIES! HELP THE VICTIM REMAIN SAFE UNTIL AUTHORITIES ARE CONTACTED. Those should be the only instructions given to elders when it comes to child abuse.