This was an appeal not to the Ohio State Supreme Court but to the State Court of Appeals. It did not concern the case as a whole but rather as to whether the lower court erred when it ordered Watchtower to produce a number of documents. The Court of Appeals ruled against Watchtower's claim of clergy-penitent privilege with the exception of four documents, which it ruled did not have to be produced by Watchtower. It ordered that the majority of the documents requested by McFarland be produced.
From the child abuse cases against Watchtower that I have read, Watchtower's appeals based on clergy-penitent privilege have failed for the most part. The differences between the states and even between the U.S. and Canada with respect to this privilege do not differ to a great degree.
Due to the way Watchtower handles these matters by involving elders, judicial committees, the service and legal departments, they rarely stay within the bounds of the clergy-penitent privilege.
I don't know what became of this 2016 case. I suspect the parties settled because I haven't heard of this case until today. If anyone has an update, I'm sure we would all appreciate hearing more about it.