It's a rare occasion when we ought to follow the directive and example of a Novus Ordo "bishop". The former "Father" Tetherow has been "laicized" and is no longer to function and be treated as a "priest". So now Fr. Pfeiffer must consider the danger MR. Tetherow can bring to his flock. Not only of his pedophilia proclivity, but of the possibility of having invalid sacraments.
Everyone in the Resistance must be warned of the great danger this Mr. Tetherow can bring.