Calvin could, of course, have made further appeal to Jerome's own opinion. Jerome, after all, cited "the common opinion of earlier times" in defense of his own very clear denial of canonical status to the Apocryphal books (as seen, for instance, in the prefaces he drafted for his Latin translation of the Bible). Jerome did, however, include -- with a clear disclaimer regarding their non-canonical status -- the Apocryphal books in his Vulgate, presumably in deference both to the merits of said books as ancient and useful (albeit uninspired) writings and to the opinion of those who disagreed with him about the canonicity of the books in question.
Jerome of course did not substitute his opinion for the decision of the Holy Spirit speaking thru the Church.
unlike Calvin, Jerome kept the peace of the Church and obeyed John 17 and 1 Corinthians 1.