OK you were right, it is correct.

At first sight this (default = difetto) looked like so many careless anglicisms, where a faint similarity in sound and meaning induces someone into believing it is a translation.

And this happens really more than needed in technical texts. My point was that you cannot trust technical people to make good translations, an it is outrageous that a translation is considered correct just because it was written in a book. But this does not apply here.

I am making up my mind that this was instead a delicate and careful intellectual construction that dutifully just failed to convey the meaning.

So be it.