Bookmarked in view of how interesting this is.
In my humble opinion, Mr. Émile Müller beat the Watchtower at its own game. Three million cheers to him for that.
Yes, "I am a doctor" is correctly translated as "Je suis médecin", but that is not the case with the word God. "était un dieu" is not the same as "était dieu", even if "dieu" is not capitalized. I invite anyone to try. Google "était dieu" and then "était un dieu", and you'll get very different meanings.
For example, I just googled the words "était un dieu", and one of the results I came upon was "quand l'empereur était un dieu", a book by Ms. Julie Otsuka. Those words mean "when the emperor was a god", and they were made in reference to the emperor of Japan, who, as we know, was was deemed to be one god, one among many; and every new emperor was another god. If "était un dieu" meant the same as "était dieu", then why is it that the writer used the definite article "un"? The writer, obviously, couldn't hold that every Japanese emperor was one and the same god, but only one of them.
What if the statement were "quand l'empereur était dieu"? Then the translation would be "When the emperor was god". You can argue that this final statement might be understood to mean that the emperor was one of many gods, not the only one, but that is not in line with the general spirit of the French language.
I think Mr. Müller was an honest man above all.
I wonder if modern versions of the French NWT include the "un dieu". That would be very revealing.