Oral Q?

Over on the Jesus Dynasty blog, James Tabor reproduces a new academic review of his book and it is by Dennis Groh. Groh has an odd note:

Behind both Matthew and Luke was an oral sayings-collection common to both and unknown to Mark. The German word Quelle (or “Q”) which means “source” was given to this collection of sayings, which most scholars suppose was never a written document, but which circulated orally beginning from around 50 CE.

I am really surprised to see the claim that "most scholars" suppose Q to be oral. I would say that quite the reverse is the case. Most scholars who accept the existence of Q suppose it to have been written, and with good reason -- the extent of verbatim agreement in double tradition is often very close. Indeed, Matthew and Luke are never as close in triple tradition as they sometimes are in double tradition.