Since you agree that one can be an anti-Humean and come to the completely opposite conclusion regarding the historical validity of the Bible as you do, that seems to go along with my point that one's a priori commitement in regards to the supernatural is irrelevant in reaching that conclusion.
If an anti-Humean after closely examining the text finds that say John has almost zero historical validity while Mark has more, then why can't a Humean using that same methodology also be allowed to reach the same conclusion?
By the way, I looked into Stephen T. Davis. He appears to be a philosopher and not a biblical scholar. At least I could see little indication from his curriculum vitae, that he is personally engaged in analyzing ancient texts in their original language. IMHO, it's much better spending the time reading scholars like Brown or Metzger or Ehrman who actually work directly with the texts than a secondary work like Mr. Davis's. But if you can point me to info regarding Mr. Davis that indicates I'm mistaken about him, I'll be more than happy to try and get a look at his book.
VR: I happen to like Davis because, as a philosopher, he is aware of the philosophical issues surrounding the study of biblical documents. To get the best answers in biblical studies you not only need to have studied the documents themselves, you need a familiarity with literary criticism in general, as Lewis pointed out, and you also have to be sure that you have a clear understanding of the underlying philosophical issues behind the study of these documents.
In 1990, I was a fellow at the Center for Philosophy of Religion at Notre Dame. There was a conference on philosophy and biblical criticism. The philosophers tended to be more traditional in their understanding of the biblical documents and were critical of the left-wing biblical scholars because of a failure to understand logic, argumentation, and the underlying philosophical issues that bore on biblical studies. The Bible scholars thought that the philosophers didn't know as much as they ought to have about biblical studies to be making those criticism. Things got very heated because the keynote speaker was Michael Dummett, a Catholic philosopher of language who had done little in the area of philosophy of religion but had blasted left-wing biblical scholarship in a recent issue of New Blackfriars. His commentator, John Collins, was very harsh in his response and said that Jesus would be turning over in his grave if he could hear what Dummett had said.
The session that was fascinating to me, was a paper read by Marilyn McCord Adams on the miracle stories in Luke-Acts. Adams had just completed a divinity degree at Princeton thoelogy seminary, but for many years she had, along with her husband Robert M. Adams, been part of a highly-regarded husband-wife team of Christian philosophers at UCLA. She argued that much of the literature concerning miracle stories in Acts was driven (that's the word she used) by an attempt to avoid accepting miracles. She then pointed out that the literature on the rational acceptability of miracle claims did not show that one should avoid accepting them at all costs, mentioning, for example, Richard Swinburne's work on the subject.
A Bible scholar next to me raised his hand and said that in his studies he had simply been following Bultmann's lead on the subject, and that he was willing to study the philosophical literature on miracles to see if there was good reason to change his mind.
The point I want to make is that you can be very versed in the original documents and not have much of an understanding of literary criticism in general, which, as Lewis points out, is a serious problem. A lot of Bible scholars seem to me to adopt what I take to be a naive Bultmannian position with respect to miracles, or are influenced by those who do. When I read a Bible scholar who believes in biblical inerrancy along the lines defined by the early Pinnock, I expect these presuppositions to affect the conclusions he draws. And the same with question of Humean presuppositions.
Can someone who is operating from Humean presuppositions give arguments that might persuade non-Humeans that a passage is not authentic? Of course. But I expect the scholar to recognize that other people just might not share their Humeanism, and to address the issue with that in mind.