Thanks for the background on this--I never thought about this bit.
It does remind me of the other equation they could not make add up properly--the dogma of the Immaculate Conception of Mary.
You know, that doesn't refer to her being made pregnant by the Holy Spirit--It is derived from the ancient and popular idea that Mary was conceived without sin thus making her a fitting receptacle for Jesus. "Holy Mary, Mother of God" as the catholics say.
It gave St Thomas Aquinas fits though--because if God could "cure" original sin so easily--which nullified the need for a blood ransom--then Mary had no need of Savior (and no one else would need saving if God could do this little parlor trick)
Quite the theological mess, and Thom had to solve it since the Pope declared it true. The only remedy he could come up with was that however her mum n dad did "it", she just for one unholy second was she a sinner--then BLAM!--cured! Immaculate conception.
Stupid.