The books of the Protestant canon are infallibly determined.
How's that?
But what does that prove?
The question at hand is, Did Luther have the authority to determine the Protestant canon of Scripture? (Specifically, the authority to remove books from the accepted canon of Scripture in his day.)
Did he act infallibly when he removed books from the Bible?
Can you say, "Luther is not infallible, and we cannot be certain that he acted infallibly when determining his canon of Scripture?"
I can certainly say Martin Luther was fallible, fallen and sinful just as we all are, including every Pope who ever lived and even Mary, indeed every single human being past, present and future on the face of this Earth save one, and that was Jesus Christ.
Martin Luther is not some stand-in for a pope, St_Thomas_Aquinas. That’s not the case even for Lutherans, let alone the rest of Christianity deemed “Protestant.”
You clearly did not read the links provided for you by Mr. Rogers regarding the ongoing controversy, right up to and beyond the Council Of Trent, regarding the canonicity of the Deuterocanonical books of the Bible. It was not merely a Protestant-Catholic issue, it was and actually is an internal matter within Catholicism.
Can you explain why you fail to grasp this?