[ansel12]

No, it isn’t plain at all.

Where is he getting the information that is supposed to be infallible?

[Legatus]

No, it isn’t plain at all.

I can't get any plainer than "God doesn't do this".

Where is he getting the information that is supposed to be infallible?

From the "Deposit of Faith" (Sacred Scripture and Sacred Tradition) left to us by Our Lord and His Apostles.