[The Iguana]

Not long after came the throwing off of the "infallibility" of the Pope altogether.

While implicit in the powers of the papacy, the doctrine of "infallibility" was not declared until 1870 - long after the Reformation. The 16th cetury Reformers had never heard of the doctrine; though they certainly were revolting against papal authority, to be sure (among other things).

It's also a badly misunderstood doctrine. Do you know how many times Pope John Paul II has officially invoked papal infallibility, speaking ex cathedra? Try "zero."

[gbcdoj]

The 16th cetury Reformers had never heard of the doctrine;

They had, actually. Trent decided to refrain from a definition, but infallibility of the Pope was already widely held in the Church and a subject of controversy with the Reformers.