For background, the Catechism of the Catholic Church (CCC) says this in section 841:
-The Church's relationship with the Muslims. "The plan of salvation also includes those who acknowledge the Creator, in the first place amongst whom are the Muslims; these profess to hold the faith of Abraham, and together with us they adore the one, merciful God, mankind's judge on the last day."
But a probably Sedevacantist commenter said:
Pope Leo X, Fifth Lateran Council, Session 12, March 16, 1517: “Our aim is to crush the Turks and other infidels standing firm in the eastern and southern regions. They treat the way of true light and salvation with complete contempt and totally unyielding blindness; they attack the life-giving cross on which our Saviour willed to accept death so that by dying He might destroy death, and by the ineffable mystery of His most holy life He might restore life; and they make themselves hateful enemies of God and most bitter persecutors of the Christian religion.”
So I fretted - what is a Protestant to do? Two Roman Catholic statements, coming from the Magisterial, authoritative RC teaching authority, but two different sets of doctrine. What's a guy to do?
The very civil and polite Theo responded, saying that
-Unless the statements you ask about were made "ex cathedra" it is possible that neither statement is totally correct.
This of course is a very unsatisfying answer for our critics who are already convinced that our teachings regarding the Church leading in all truth and our simultaneous teachings that even the most high official can make errors demonstrates mere sophistry. Add to that that even in cases of dogmatic statements, we do not rule out that their understanding can be clarified and corrected as we continue to learn more about God's infinite kingdom, and I can see how critics must simply want to jump all over it.
The bottom line is that what you seem to demand that we should mean by infallible pronouncements of the Magesterium is something like "everything every church council or official ever says is infallible and must be taken by Catholics as the absolute truth, or they are being false to their teaching. Whereas we understand such pronouncements to be very limited in occurrence, and even then not subject to private interpretation, just as Scripture itself is not subject to private interpretation.
...this whole "I want infallible statements!" is not coming from ME. It's the standard laid down by RC apologists, who criticise Sola Scriptura by saying that it does not solve the problem of fallible individual interpretation.
So then I mention the difference that is obvious between 5th Lateran Council and the CCC. Anyone can see the difference.
And now I'm getting "well, it's not clear which one is infallible". How then does that help the person who takes the claims of these RC apologists seriously? If RCC can provide infallible interpretations, why don't you ever know if it did or not?
That alone is enough to disqualify such statements as special pleading and silly, to say nothing of the fact that an infallible teaching authority simply pushes the fallibility question back one step.
Though this is not on a subject crucial to individuals' salvation, it is very illustrative of the modus operandi of RC apologists.