The RCC has infallibly stated the Vulgate is doctrinally correct.
The Vulgate rendered the Hebrew CHATTA’AT as peccato and this was translated into English by the Catholic Douay Rheims as “sin.”
I didn’t do it.
Leviticus 12:8 And if her hand find not sufficiency, and she is not able to offer a lamb, she shall take two turtles, or two young pigeons, one for a holocaust, and another for sin: and the priest shall pray for her, and so she shall be cleansed. -Douay Rheims faithful translation of the doctrinally correct Vulgate
As “sin” that is “not sin” cannot exist being a contradiction in terms, the RCC dogma of a “sinless Mary” offering a turtledove “for sin” is impossible.
Therefore the RCC is doctrinally at odds with the Vulgate which they said is doctrinally correct, they have infallibly declared contradictories as both correct.
Hence One or both of their infallible statements are in error and as God’s teaching authority would never teach doctrinal error the RCC cannot be God’s teaching authority.
Moreover the dogma of a sinless Mary is in hopeless paradox.
If Mary were sinless when she offered sacrifice for sin that doesn’t exist THEN she sinned by trampling upon the Law of the LORD which does not require the innocent pay penalty as though they are guilty.
Sacrificing to God what He did not command is rebellion against God, a sin, the sin of Korah and his troop, also Nadab and Abihu:
DRA Leviticus 10:1 And Nadab and Abiu, the sons of Aaron, taking their censers, put fire therein, and incense on it, offering before the Lord strange fire: which was not commanded them.
Moreover it is an offensive act to slaughter animals for sin offering when there is no sin liability, that is senseless killing.
Therefore if Mary were sinless then she became a sinner indeed by her needless slaughter harmless and inoffensive turtledoves, and by rebellion against the Law of Moses as recorded in the doctrinally correct Vulgate.
Some have suggest Mary only thought she was a sinner, 19th century popes with the charism of teaching know her better than she did herself!
Talk about violating Occam’s Razor!
However even if it were possible a person born sinless would still think they are sinners, the paradox still exists as the law of Moses identifies violations done unwittingly or in ignorance as sin requiring sacrifice for sin:
Leviticus 4:2 2 Say to the children of Israel: The soul that sinneth through ignorance, and doth any thing concerning any of the commandments of the Lord, which he commanded not to be done:
So a sinless Mary wrongly believing herself to be a sinner would not excuse the needless slaughter of Turtledoves and sinful rebellion against the law of God by offering sacrifice for reparation of unbroken atonement.
Then her disobedience to the law of Moses, ignorant and unwilling as it be, is sin and Mary is no longer sinless.
Clearly the RCC Magisterium, which has infallibly decreed doctrinal error as correct, cannot be God’s Teaching Authority.