Greendawn,
I wouldn't say that 'Biblical Greek has nothing to do with classical Greek', One scholar calls Hellenistic Greek 'the later vernacular Attic' and points out that foreign influences were 'not enough to change the essential Attic character' (A.T. Robertson, A Grammar of the Greek New Testament in Light of Historical Research). I presume that Hellenitic Greek is far closer to Attic (Koinh) than to modern Greek. At any rate, Gangas would probably have studied classical Greek (early Hellenistic Greek if you will) and would have heard Hellenistic Greek from his youth on. He may well have studied Hellenistic Greek as well, perhaps Greek from all of the major periods.
Until I heard the radio program, I had no idea that Greeks so routinely studied their ancient literary works. It was, therefore, a safe assumption to make that Gangas was no more qualified than you or I to translate Hellenistic Greek. I now assume otherwise unless someone has reason to believe that his schoolboy training was radically different than that of a normal Greek's.
Of course, that doesn't mean that he was as qualified as someone trained at university/seminary, nor that he wasn't biased by his affiliation with the Watchtower Society. Also, the other members, besides Franz, were apparently untrained in Biblical languages. An added point would be that Gangas probably was entirely unacquainted with Hebrew or Aramaic. I'm not contentending that the committee as a whole was qualified, I'm just surprised that an additional member of the committee probably was at least somewhat familiar with Hellenistic (koinh) Greek, contrary to many what commentators have expressed or implied. I suppose it's good to be accurate, and honest, if we're ever in a debate.
Consider the above a friendly 'heads up'.