I made no such claim. The Council of Rome was a local council, and as such, like the North African councils, does not have the charism of infallibility. It does, however, give evidence to the acceptance of the Deuterocanonical books in the West. I did not intend to say that any of those citations were formal infallible decrees of the Church. Rather, they are evidence of what was the generally accepted teaching. This day to day teaching of the Church is Ordinary Magisterium, or Teaching Authority, and enjoys the same infallibility as those formal decrees of ecumenical councils or proclamations of popes. It is typical of the legalistic mentality of Protestants to discount anything other than formal legal decrees.
and depends upon the Decretum Gelasianum, the authority of which is disputed (among RC's themselves), based upon evidence that it was pseudepigraphical, being a sixth century compilation put together in northern Italy or southern France at the beginning of the 6th cent.
Disputed, yes, but not conclusively denied. But even if it were to be agreed that this is a work of the 6th century rather than that of the of 4th, it would still show that the Deuterocanonical books were accepted then.
To the contrary, the testimony of history is that these were not considered to be even close to infallible (requiring assent of faith) or requiring religious assent (of mind and will, and forbidding public dissent, at least as per later official teaching), but was a matter one could validly and publicly express different opinions on, which is only what Luther did.
And where was even Luther's opinion on the canon made a real issue by the contemporary Roman powers that be? I have not seen it.