I thought it had been harrumphed, not actually disputed!
Starting from those passages that are unclear to the Western commentators, the method runs as follows. First check if there is a plausible explanation in Tabarī that the Western commentators overlooked. If not, then check whether the Lisān records a meaning unknown to Tabarī and his earlier sources. If this turns up nothing, check if the Arabic expression has a homonymous root in Syriac with a different meaning which fits the context. In many cases, Luxenberg found that the Syriac word with its meaning makes more sense. It is to be noted, that these first steps of the heuristic do not emend the consonantal text of the Cairene edition of the Qur’ān.
 If these steps do not avail, then see if changing one or more diacritical marks results in an Arabic expression that makes more sense. Luxenberg found that many cases are shown to be misreadings of one consonant for another. If not, then change the diacritical point(s) and then check if there is a homonymous Syriac root with a plausible meaning.
 If there is still no solution, check if the Arabic is a calque of a Syriac expression. Calques are of two kinds: morphological and semantic. A morphological calque is a borrowing that preserves the structure of the source word but uses the morphemes of the target language. For example, German Fernsehen is just the morphemes tele and visio of English “television” translated into their German equivalents. A semantic calque assigns the borrowed meaning to a word that did not have the meaning previously, but which is otherwise synonymous with the source word.
 In section four, Luxenberg presents the development of the Arabic script and its central importance to the transmission history of the Qur’ān. He demonstrates that there were originally only six letters to distinguish some twenty-six sounds. The letters were gradually distinguished by points written above or below each letter. The Arabic alphabet used in the Qur’ān began as a shorthand, a mnemonic device not intended as a complete key to the sounds of the language. Luxenberg concludes that the transmission of the text from Muhammad was not likely an oral transmission by memory, contrary to one dominant claim of Islamic tradition.