It might be a little off-topic, but hearing him he sounds to me as a presumptuous, haughty man. Why mention Oxford so many times speaking about your self. Besides when you get outlines for a talk on any assembly it always says not to draw the attention to one as a speaker (jokes, personal things), and look what he does.
I personally (might be a Dutch thing, we don't like snobbish people in general) always hated jw's talking about what they could have been if they wouldnt have been a jw.
Anyway, if Franz dominated Koine, he was lucky just to have to read it and write it. I have heard him in Spanish (an old recording a mexican brother had), it was more Kentucky with a Spanish accent.