That was a mercy on the part of the Church, but his theology is not the mind of the Church as newly defined in V-II. Truly, the footnote #19 in L.G. says the teaching came from this very letter to Feeney.
(19) Cfr. Epist. S.S.C.S. Officii ad Archiep. Boston.: Denz. 3869-72.
Quoting myself:
"Rin:
He was at odds with the “mind of the Church” for certain
It’s quite obvious that he was. Additionally, he was in my opinion
wrong. But neither being wrong nor being at odds with the mind of the Church makes one a heretic. To paraphrase my dogmatics professor, “you can deny that diaconal ordination is part of the Sacrament of Holy Orders if you so wish without being a heretic, but you would be an oddball”. It has only been infallibly declared that sacerdotal ordination is part of the Sacrament, but one would of course be seriously out of sync with the mind of the Church if one rejected that a deacon is sacramentally ordained. Refusing to see episcopal consecration as part of the Sacrament is more common (I know of respected theologians who avoid teaching sacramental theology over it), but still at odds with the mind of the Church. But neither are heresies.
Not to derail, but this is untrue. They have applied for canonical recognition, but at this point in time, they are still not recognized. It may be true that they are allowed to hold that belief in their community, but Feeney was broadcasting prolifically with printed material to promote his agenda, and this is what the Church clamped down on.
I stand corrected - they are not canonically recognized by Rome.
They are however regularized in their diocese - from their
website:
Saint Benedict Center:
In 2002, Bishop Reilly of Worcester came to the Center and after a ceremony in the Chapel where the community recited and signed a copy of the Creed, he gave his formal blessing and “regularized” the community in the diocese.
They still insist on their literalist interpretation of EENS. Yet, they are in full communion with the Church, and recognized by their diocese. Again, their position is not heretical.
But I’m not really out to defend them - I dislike their position heavily, and many ultraconservatives would probably view my unwillingness to proclaim hellfire upon non-Catholics, even non-Christians (I have a hard time accepting that the millions upon millions of people of good will who have never heard the Gospel proclaimed in its fullness are to perish just for growing up in the wrong areas of the world) as bleeding-heart liberalism, while in reality my view falls within orthodoxy too. So I’ll reserve detailed debate about Feeneyism for another time, or preferably never

. It’s just important to remember that on some areas, disagreement is legitimate - even on soteriology. Perhaps
especially on soteriology. His excommunication was because of his defamation of the Magisterium, not because of his theological position.
Something that has been taught unanimously for 2,000 years is indeed infallible. That’s the meaning (…)
Look, I’m not advocating anything. I’m simply asking questions. And I’m not really asking you, or anyone else on this forum. I’m “asking” the bishops and the Pope, and sharing my questions here. And we’ll see how they conclude.
As for perennial unanimous teaching and infallibility, you are technically correct. The question is
whether a specific teaching has been taught unanimously. And in some cases, it’s a question of
what has been taught. It’s not always as clear cut as you might believe; there is a reason why we have theologians.
EENS is a great example of something “everyone” thought had been taught unanimously (and it had!), but it turned out our understanding of it was insufficent. The change of interpretation by the mainstream Church was so radical that it caused a semi-schism. A minuscule one, but still a semi-schism.
And to conclude, I stand by my words about conservatives being too trigger-happy with the infallibility trump card. Websites such as this one are teeming with it.