Here's a primitive outline, thrown together in about 2 minutes, of typical rule inventing of a Romanista soldier as compared to Romanist Worldview Headquarters. The following is based on an argument against my position on Luther and the canon.
Romanist Worldview Headquarters: Trent infallibly declared the contents of the Canon. Previous to that, there was freedom to express opinions on canonicty. See, we're not so bad. Previous to infallible declaration, enjoy your speculations.
Romanista response: Luther taught sola fide, which is a false gospel, so he was a heretic, and wasn't allowed like Cajetan the freedom to express an opinion on the canon.
Romanist Worldview Headquarters: Justification was defined at Trent, so Luther can't be chastised for sola fide.
Romanista response: C'mon, Luther was declared a heretic, so he didn't have any right at all.
Romanist Worldview Headquarters: Romanism never condemned Luther by name at Trent, and no official judgment on Luther exists by which a loyal Catholic is bound.
Romanista response: Luther is still a heretic, and took books out of the Bible.
Romanist Worldview Headquarters: We don't have a rule that says heretics should be chastised for doctrines not yet infallibly defined, or that we can take a later rule and apply it to them to declare their opinion heresy.
Romanista response: I don't care, I'm protecting you, so stop giving me a hard time. Don't you remember Exsurge Domine?
Romanist Worldview Headquarters: Was Exsurge Domine an infallible document?
Romanista response: Well no... but... Luther took books out of the Bible! Do something about it!
Romanist Worldview Headquarters: Would you like a rule that says: Luther was a heretic, and even if he did what our leading sixteenth century Romanista Cajetan did, Cajetan was OK, and Luther was not?
Romanista response: Yes! Perfect! Please, declare that rule!
Romanist Worldview Headquarters: Our infallible council meets on and off and every few hundred years. If you can wait, maybe we'll put something together.
Update: Here's another 2 minutes of thoughts on this issue:
As far as I can recall, none of the Reformers are named in Trent's infallible declaration.
It was Hubert Jedin, the German Catholic historian from the Universities of Breslau and Bonn, a specialist on the history of the Council of Trent that pointed out Roman Catholicism never condemned Luther by name at Trent, and that no official judgment on Luther exists by which a loyal Catholic is bound.
This makes the "What to do with Luther" rather interesting from a Roman Catholic perspective. Gregory Sobolewski has compiled quite a book addressing this issue: Martin Luther: Roman Catholic Prophet (Milwaukee: Marquette University Press, 2001). Sobolewski traces more recent Roman Catholic scholarship and their positive attitudes toward Luther. It was interesting to read how many Roman Catholic scholars don't think Luther was a heretic. Some go as far to point out how spiritual and necessary Luther was to the Roman church.
It's true Trent didn't declare Luther a heretic in their statement. However, in 1564 the Tridentine Index of Books condemned Luther's writings. Here's the closest you get to the goods on Luther. Still, this doesn't help the Romanista that tries to argue Luther's can't comment on the canon while Cajetan and Erasmus can. Why Romanistas try to make up there own rules is just another example of how people reason from their heart, not history, or even consistently with their own worldview.