Maybe we should read some Scripture commentaries by the Fathers and Doctors rather than try and figure it out for ourselves?
Cornelius a Lapide on Luke 22:31Note how it says nothing about infallibility or ex cathedra, but his teaching in general.
Yessiree. The Church cannot teach major error or heresy in Her authentic magisterium, but she also cannot defect in the way that some Sedevacantists imply; especially Totalists.
As Papa Pio NoNo said about the heretical & schismatic Old Catholics:
“Incredibly, they boldly affirm that the Roman Pontiff and all the bishops, the priests and the people conjoined with him in the unity of faith and communion fell into heresy when they approved and professed the definitions of the Ecuмenical Vatican Council.
Therefore they deny also the indefectibility of the Church and blasphemously declare that it has perished throughout the world and that its visible Head and the bishops have erred. They assert the necessity of restoring a legitimate episcopacy in the person of their pseudo-bishop, who has entered not by the gate but from elsewhere like a thief or robber and calls the damnation of Christ upon his head.”
Totalists Sedevacantist ecclesiology is simply not tenable. In fact, it’s impossible.
The only way to reconcile Traditional ecclesiology with indefectibility in teaching is by adhering to a variation of Msgr. Lefebvre’s Conciliar church/eclipse hypothesis like Fr. Chazal’s Sedeimpoundism or Msgr. Des Lauriers’ Cassiciacuм Thesis.
Objectively considered, Recognize and Resist outside of the above paradigm and Totalist Sedevacantism are both worthy of being condemned as heretical comedy bordering on the insane.