I think Neuwirth's position might be a result of the following findings of Sadheghi..
http://www.scribd.com/doc/110978941/San ... -An#scribd
Sadeghi has documented his findings based on the textual criticism method. Many muslims seem to quote Sadeghi that he has proven based on Stemmatics that uthmanic quran was the most accurate representation of the prophetic type. I have responded to the argument below..
I do not agree with everything that Sadeghi has written. However one thing caught my attention. He says that some companion codices found in Sanaa which is called C1 has some of its variants exactly the same as that of Ibn Masud and Ubay. The variant readings in codices of Ibn Masud and Ubay have been documented by islamic scriptures. However its equally true that C1 disagrees with their texts on many counts. The point I am getting at is - There is some degree of truth to what islamic scriptures report regarding the actual variants. It cannot be a coincidence that islamic scriptures were fabricated to show variants in copies of Masud and Ubay and the same thing (some parts and not all) were found as it is in Sanaa manuscripts some 1400 years later. This might be the reason as to why Neuwirth does not agree with western academicians who claim that entire islam is a fabrication.