[bill_from_tampa]

The author mentioned that some of the "Q" sayings in Matthew have been modified and are worded a bit differently in Luke, and seemed to believe that this was an argument more for a separate "Q" source than for the hypothesis that Matthew added the "sayings of Jesus" to the framework of Mark to produce the gospel of Matthew. This does not make any sense to me -- Luke could have altered the wording of the "Q" document just as easily as the "Jesus sayings" in Matthew! And both Matthew and Luke tell the story a bit differently than Mark, and sometimes this is for pretty obvious theological reasons or to 'fix' problems they believed Mark contained. If Matthew didn't see the need to edit and change Mark, and Luke see the need to edit and change both Mark and Matthew, why did they write new gospels anyway?

tl;dr The Farrer hypothesis seems much simpler and more likely.