That's exactly right.  These posters either 1) didn't even read Fenton, 2) have very poor reading comprehension skills, 3) feel the need to distort Fenton in order to refute their false strawman representation of what he actually said.  It's probably some combination of these 3 factors.  Then there was the typical Stubbornian gratuitous dismissal of Fenton as being "no good" (in the past he's dismissed all "19th and 20th century theologians").  When Stubborn produces a screenshot of his doctorate in theology, I might spent 2 seconds considering his claims.

Fenton was speaking about an aspect of the Church's indefectibility, that the Pope is protected by the Holy Spirit from leading souls into grave, substantial error, since such a thing would be incompatible with the promises of Our Lord for the papacy and for the Church (as Vatican I taught and as Archbishop Lefebvre affirmed).

+Lefebvre:

John 7:41-47

 41 Others said: This is the Christ. But some said: Doth the Christ come out of Galilee?  42 Doth not the scripture say: That Christ cometh of the seed of David, and from Bethlehem the town where David was?  43 So there arose a dissension among the people because of him.  44 And some of them would have apprehended him: but no man laid hands on him.  45 The ministers therefore came to the chief priests and the Pharisees. And they said to them: Why have you not brought him?


46 The ministers answered: Never did man speak like this man.  47 The Pharisees therefore answered them: Are you also seduced?  48 Hath any one of the rulers believed in him, or of the Pharisees?  49 But this multitude, that knoweth not the law, are accursed.

For the reasonings of any men whatsoever, even though they be Catholics, and of high reputation, are not to be treated by us in the same way as the canonical Scriptures are treated. We are at liberty, without doing any violence to the respect which these men deserve, to condemn and reject anything in their writings, if perchance we shall find that they have entertained opinions differing from that which others or we ourselves have, by the divine help, discovered to be the truth. I deal thus with the writings of others, and I wish my intelligent readers to deal thus with mine.


Augustine, Saint. The Complete Works of St. Augustine: Cross-linked to the Bible and with in-line footnotes (p. 1534). Kindle Edition.

The pope is only infallible or "infallibly safe" when he (to use Fenton's explanations) is

a) issuing a directive/command,  (which implies it is of a binding nature, which implies sin is involved for disobedience)
b) to the entire Church

This is why one can say Quo Primum is "infallibly safe", for since it does not deal directly with doctrine/morals, Pope St Pius V makes it clear (multiple times) he is enforcing a law, using his apostolic authority to command that, only his missal can be used (with certain exceptions), which directive applies to the entire Church.

Any papal act outside of the above, which does not fulfill the conditions, is not infallible/infallibly safe.

I've been saying this for YEARS.  Glad Fenton backs me up, because I read this from other theologians/books.

... God has given the Holy Father a kind of infallibility distinct from the charism of doctrinal infallibility in the strict sense. He has so constructed and ordered the Church that those who follow the directives given to the entire kingdom of God on earth will never be brought into the position of ruining themselves spiritually through this obedience. Our Lord dwells within His Church in such a way that those who obey disciplinary and doctrinal directives of this society can never find themselves displeasing God through their adherence to the teachings and the commands given to the universal Church militant. Hence there can be no valid reason to discountenance even the non-infallible teaching authority of Christ’s vicar on earth.
...
The nature of the auctoritas providentiae doctrinalis within the Church is such, however, that this fallibility extends to questions of relatively minute detail or of particular application. The body of doctrine on the rights and duties of labor, on the Church and State, or on any other subject treated extensively in a series of papal letters directed to and normative for the entire Church militant could not be radically or completely erroneous. The infallible security Christ wills that His disciples should enjoy within His Church is utterly incompatible with such a possibility.
...
Ultimately, however, this assent is not the same as the one demanded in the formal act of faith. Strictly speaking, it is possible that this teaching (proposed in the encyclical letter) is subject to error. There are a thousand reasons to believe that it is not. It has probably never been (erroneous), and it is normally certain that it will never be. But, absolutely speaking, it could be, because God does not guarantee it as He guarantees the teaching formulated by way of definition’.