> To the extent the author’s point relies on the incorrect definition, it cannot be consistent or correct.

I don't think that a point based on an incorrect definition is automatically inconsistent or itself incorrect. It might be, of course, or it might just be insufficiently justified. And, to the extent that it is a philosophical point rather than a historical one, the truth or falsity of a philosophical claim doesn't depend on whether someone actually said it, or it is a mistranslation of something someone actually said.