This is the last time I'll say this.. The question wasn't worded specifically enough.
All JW's believe they are acting as God's spokesmen, every time they preach.
It wasn't a lie.
At best we seem to have an example of a GB member giving a misleading and nonspecific answer, to a nonspecific question.
Then again, asking:
"Are the Governing Body God's only channel of communication on earth today?" would, now I think about it, have produced a response like: "Well, we are certainly a part of that channel."
Can we move on to a more interesting topic:
What question would have forced Jackson to admit that the Governing Body see themselves as being the ONLY people on this earth who can interpret the Bible correctly, with God backing everything they put in print?