(Related to Are Muslims fit to be Noahides?. ) The question came up there, are the Muslims heretical (in our view) because they reject our Torah as we currently have it?
This is based on a gemara Sanhedrin 99a, quoted by the Rambam in Hilchos Teshuvah:
It is taught in another baraita: “Because he has despised the word of the Lord”; this is a reference to one who says the Torah did not originate from Heaven. And even if one says the entire Torah originated from Heaven except for this verse, i.e., any one verse, claiming that the Holy One, Blessed be He, did not say it but Moses himself said it on his own, this is included in the category of: “Because he has despised the word of the Lord.”
My question: We know that there are disagreements on various versions of our Sefer Torah, an extra or missing vav here or there, an aleph in place of the hey there. How far can one disagree with the current version (say, in the Aleppo Codex) without falling afoul of this gemara?
After all, the text of the gemara is "but Moses himself said it on his own" (אלא משה מפי עצמו). That isn't what I'm asking here. I'm asking, if someone says, "For sure the entire Torah is exactly what G-d gave Moshe. Not one letter was made up or added by Moshe, ח"ו. But I think that posuk was a copying error later, by mistake."
Obviously this kind of thing lends itself to outrageous abuse and people playing games. I've heard that the Muslims claim that we switched Isaac and Ishmael in the Akeidah, ח"ו! [This example illustrates that someone doing this is likely to run afoul of some other issues, like trust in our Sages and their transmission.] I'm asking about an honest sincere Bible critic, say, if there is such a thing.
(This came up because I heard today that some secular scholars make exactly such claims about the Ibn Ezra; I know nothing about the details, maybe others do. But I just heard a chareidi chacham reject such claims because, "Chas Vashalom!, the Ibn Ezra wouldn't believe something heretical!" So that would go into my question: Is it possible someone could believe that because there's nothing really wrong with it?)
Added: I am assuming here that the answer to the related question How can the Rambam's Eighth Principle of Jewish Faith be believed in light of Hazal? is the one given there in the name of Rav Yaakov Weinberg z"l: The Rambam's Eighth Principle is not concerned with the accuracy of our current text.