If, as seems likely, scribe A wrote the gospels in sequence this would require everyone at the time to have missed the supposed major blunder or blunders by scribe A in Matthew, scribe D to have been called in to replace the Mark–Luke bifolium, the exercise of putting in the canon tables to have been called off during this exercise, and then and only then for scribe D to have been called in to firefight the newly discovered serious (though entirely hypothetical) solecism by scribe A in Matthew. This is all very implausible.
Hence we know what are called clerical errors to an enormous extent in the Sinai MS., partly because, though beautifully written, it abounds in slips ocular and orthographic. Not only is there the very frequent fault of confounding o, ov, v, and w; ci, n, ai, and i, but in repetition of letters, words, and whole sentences, sometimes left, often cancelled. Mr. Scrivener mentions that the blunder technically known as Homoeoteleuton, whereby a clause is omitted because it happens to end in the same words as the clause preceding, occurs not less than 115 times in the New Testament, though the defect is often supplied by a more recent hand.
8 For the issue of itacism in general and the common occurrence of the ei—i
and at—e interchange see e.g. F.T. Gignac, A grammar of the Greek papyri of the Roman
and Byzantine periods 1: Phonology (Milano 1976) 189-193; E. Mayser, Grammatik der
griechischen Papyri aus der Ptolemderzeit mil Einschluss der gleichzeitigen Ostraka und der in
Agypten verfassten Inschrifien I haul- und IVortlehre; /. Teil Einleitung und Laullehre, 2. Auflage
bearbeitet von Hans Schmoll (Berlin 1970) 66-70 and 85-87.
For the role of itacism in the transmission of the text of the New Testament see C.C. Caragounis, The Development of Greek and the jNew Testament: Morphology, Syntax, Phonology, and Textual Transmission (WUNT 167; Tubingen 2004) 496-502.