PS: As an aside, after BXVI was elected (ie., the first pope to be elected who was consecrated according to the new rite), a firestorm of debate regarding the validity of the new rite ensued.
I would have to go back and refresh my memory regarding all the arguments coming from the SSPX and Avrille in defense of validity, and Fr. Cekada and Rore Sanctifica against validity, but I do not recall either side alleging that the new rite of episcopal consecration was covered by infallibility, indefectibility, or as a secondary object of infallibility.
Correct me if I am wrong, but it seemed most of the debate centered around whether or not the essential form was sufficiently univocal or invalidly ambiguous.
If my memory is correct in this regard, it is an interesting concession by both sides.