Ittur Soferim

Marc B. Shapiro, in his book The Limits of Orthodox Theology: Maimonides' Thirteen Principles Reappraised p. 111, states that R. Ashier ben Yehiel (the Rosh) is of the view that the Men of the Great Assembly (scholars around the time of Ezra) removed various letters in the Torah, a process called "Ittur Soferim." Additionally, the Netziv cites this Rosh approvingly, implying that this great rosh yeshivah also agreed with this view.

I found this hard to believe because the Gemara (Nedarim 37b) calls Ittur Soferim a halakhah le-Moshe mi-Sinai, something told to Moshe at Mt. Sinai and passed down in tradition. So I looked up the Rosh. What he really says is that Ittur Soferim are letters that were removed from the Torah but should have been in it. He never says who did it. One could easily (and more plausibly) read the Rosh as saying that there was a tradition from Sinai that certain letters that, grammatically, should have been in the Torah were never put in, i.e. they were removed from the sentences at the time of writing. See also the Arukh (`ATR 2).