Many observations can and must be made about [Scott] Hahn’s thesis. First, in regard to the authority of the church in ascertaining historical data such as the authorship of the gospels, Hahn has simply confused authority with historical reliability. Just because a person living during the Civil War era happens to record through written correspondence that Abraham Lincoln authored the Gettysburg Address, do we thereby attribute authority to this person in all historical matters about which he writes? (Eric D. Svendsen, Evangelical Answers: A Critique of Current Roman Catholic Apologists [Lindenhurst, N.Y.: Reformation Press, 1999], 10, italics in original)
There is, moreover, good reason that the men in these synods did not view themselves as infallible in their decision—the Roman Catholic doctrine of infallibility was not defined until 1870. While there is evidence to suggest that the early fathers viewed themselves as authoritative in their collective decisions, and that the church itself id indestructible, no church council for the first millennium of Christian history claimed infallibility in its decisions; and the notion of papal infallibility was not proposed until around the fourteenth century. (Ibid., 13, emphasis added)
Authority was granted directly by God randomly, and without respect to current ecclesial authorities. (Ibid., 16, emphasis added)
So far from teaching Peter’s infallibility to define dogma (much less, sacerdotalism), this passage [Matt 16:18-19] teaches that Peter (and the other apostles according to Matt 18:19) will be (unwittingly) carrying out what has already been sovereignly decreed in heaven. (Ibid., 19)
[the earliest Christians] would be able to do this [trust the OT and later NT canons] on the assumption that the Holy Spirit occasionally gives infallible guidance, especially where it concerns the recognition and preservation of his word, and in spite of the fallibility of the agents he uses. (Ibid., 71-72)
Yes, some of the books were disputed at times; but there was always final consensus at some point. (Ibid., 72—note, sometimes it took centuries for some books to be universally accepted, such as the book of Revelation)