The audacity of confirming the validity of this man doing ministry in the name of the Lord when not part of the company what RCs consider to be their church. For the traditional (not this pope's) Catholic position is that no one has the commission and the right to preach the gospel if not sent by her, and that "he that hears/reject you, hears/rejects Me," does not apply to Prots.
Is that what you were taught in Catechism?