Perhaps I misunderstood the question, but I thought Dr. Fantham's question was not so much about pronunciation of Latin as it was about the authenticity of language other than what we have recorded as polished speeches and so forth. What sort of language did the common people use in their everyday lives? I suspect that the uneducated people used as much slang, made as many errors in grammar, and mispronounced as many words as people do today in whatever language they speak. How does a modern author or translator of classical works deal with that? A British author might employ a Cockney accent, or an American author might rely on a Brooklyn accent to evoke a certain feeling. Is that what Dr. Fantham was getting at?