Ooops, my mistake on the tautology thing. I don't know what I was thinking there: maybe I mixed two or more JW apologetic points into one.
Sure Witnesses retrospectively contrive arguments as you point out here concerning John 1:18, and so do Trins of course. They used to justify "and the Word was God" on Colwell's "rule", then they took on Harner's explanation when it made their point better. Whatever the different sums involved, they make sure the answer is always the same. (The old three in one)
A better example of overtranslation in the NWT in my opinion is Rom 13:1 "the existing authorities stand placed in their relative positions by God". What is the semantical basis for the qualification that the authorities stand in their "relative" positions? I don't know any other translation that uses such an adjective here, and I have not seen any Watchtower explanation either; but it sure fits in neatly with their "relative subjection" doctrine.
Incidentally the NWT in this verse betrays internal Watchtower politics somewhat. In 1950 when the NWT of the Christian Greek Scriptures was released the Witnesses still officially held to Rutherford's belief that the superior authorities were Jesus and Jehovah. However Fred Franz had never agreed with that explanation as Ray Franz explains:
I recall my uncle telling me one day in his office of an occasion when Rutherford presented a certain issue, a new viewpoint, to the Bethel family for discussion. [The footnote suggests this was either on Rom 13:1 or the elder arrangement, I here assume it was in fact about Rom 13:1] My uncle related that in the discussion he expressed himself negatively about the new view being advanced, doing so on the basis of scripture. Afterward, he said, President Rutherford personally assigned him to prepare material in support of this new view, although he, Fred Franz, had made clear that he did not consider it scriptural. (CofC 2002. pp. 65-66.)
So when Fred Franz prepared the NWT he overloaded this particular verse with his own (undoubtedly correct) view that the superior authorities are governments by adding the word "relative". It was still another 12 years until Franz finally got Knorr to change the doctrine officially in the Watchtower in 1962. So Franz got his way in the end, though he had to wait a long time after Rutherford was gone. I think it also illustrates the power handed over to Franz in the NWT project when he was able to amend doctrines he had disagreed with. You get the impression of Knorr as being somewhat oblivious to the power this handed Franz, and unaware that this meant changes until it was too late.
I think if BeDuhn had understood Watchtower internal politics better, and had focussed on verses relevant to that, he may have gained a different impression of the NWT's overall integrity.
Slim