The current Christian scripture was set by the Council of Nicea, in something like 300 AD. At that time, the catholic church had nothing llke the structure it has today. There was no supposed infallable pope at the time; for that matter, the council was convened by Constantine.

And if you believe any Jew would accept the authority of a Christian pope over their holy writings, you're crazy.

*My* understanding is that scholars think some of the Old Testament books were written by several people, and others by one, and some may have been pre-dated to have the appearance of authenticity.