That's interesting. I am sometimes tempted to think there is sone combination of words, or some argument so water tight, that upon hearing it any Witness will say 'oh yeah, the Truth must be wrong about that'. I know it doesn't work like that but it is still tempting to think.
I hope on some level I caused him to at least consider that the watchtoower might be wrong about something. JWs make a big thing about making mistakee in the past and not being infallible, right? They should at least be open to the Watchtowrt being wrong on some things. It seems they only accept changes that are directed internally.