In a matter so grave as Sacramental validity, we must abstain where the suspicion is credible.
Trying to say that it is about "evidence" is a deliberate (and quite frankly retarded) distraction.
Our Lord Jesus Christ did not choose the Thuc line to preserve his Church, He chose the Lefebvre line. A mentally stable man, with no accusations at all of withholding intention.
Folks, dont be a Thuc-tard. Its pathethic.