I wrote that paper a few months ago.Who said it was debunked?
I realized you asked razorbak, but I have a few minutes to comment.
There's a lot of research behind the documentary hypothesis but from what I can tell, much of the past 100 years of scholarship is ignored, and a lot of that scholarship demonstrates the documentary hypothesis to have a bad foundation, and then some.
It's been about 12 years since my own study on the subject so I can't remember too much. Some of the names I remember are Wellhausen and Graf (of course). Speiser, Casuto and Claus Westerman come to mind as well. I remember Westerman had reservations about the DH but went along with the others. Those who didn't subscribe to the DH that I read were Kikawada, Harrison and Young all of whom shed a lot of light on the subject with more recent scholarship.
I believe Speiser said in his commentary on Genesis (Anchor) that the point of departure for the DH were the changing names for God. But this point of departure was based on incomplete research. I say incomplete because within a very short time there was a lot more information available that demonstrated the changing names for God weren't a valid point of departure.
As I said earlier in the thread, Genesis 2:4 uses "LORD God" in the same verse. That's Yahweh Elohim, two different names for God supposedly used by different authors... only both names are in the same verse, and that blows the theory right there. Proponents of the DH don't have an answer for Genesis 2:4.
Doublets and parallels, another criteria/criterion? used as a form of source criticism turned out to be a common literary device used at the time.
Some of the DH proponents thought the various names for God were made known at different times/eras, but more recent scholarship demonstrates that to be false.
There is a lot more but I just can't remember at this time and I'm traveling too much to get my notes on the subject.
Also, I remember reading how some folks ran the text of the Pentateuch through some sort of system that checks writing style. From what I remember their results came back stating there were a few authors to the Pentateuch, not just one. Then they (or somebody) ran their own work through the same system and it reported 35 (or something like it) different authors when there were really only two. You have to take these kinds of reports for what they are.
I wish I had more time for this as I find the subject quite fascinating.