That title reads as though all the victims of a priest, accused the Bishop as covering it up.
That is not what the article said. The Pope has no evidence the Bishop knew it was happening and covered it up.
A Bishop is over many churches. We never see the Bishop in our Catholic Church. Our Priest could do something against the church teaching in private and the Bishop wouldn't hear about it unless someone went to him and told him. Now, if one of the victims went to the Bishop, that would be a different matter - from what I read, that didn't happen. They are assuming the Bishop knew.