I might see that as one he perhaps missed rather than as a tackle he allowed.
A recent thread had NO call, "on the shoulder" as a response to a cry for the high tackle.
I suspect, had they cried for it in this situation, he would have had to have a thought and given it. He couldn't really have designated it, on the shoulder or, unavoidable because MB was already going to ground.
I think he would have certainly clarified in that instance. It's his style I think.