Don't want this thread to turn political, but...
Have you noticed that just about every administration response to Scott McLellan's new book attacks the messenger? "He's disgruntled"..."It's not like him"..."We're disappointed he chose to do this"....etc. Not one word (that I have seen or heard) disputing the actual contents of the book.
Sound familiar? What do you read in the Watchtower? "Apostates have allowed pride to overcome them"...."Satan has overreached them"...."They bitterly 'beat' their former associates"...etc. Once again, nary a word contesting the actual arguments apostates promote.
If you are "working" on reasoning with a JW, perhaps the McLellan book & the Bush team response is way to broach the logical fallacy of "attacking the messanger".
Mention the book, the Bush team's response, and how they are vilifying the author without refuting his arguments. Ask if they think that is fair or reasonable..."why don't they refute his arguments...or is their silence a tacit admission that what he says is true?" A halfway-reasonable JW should be able to see the point.
Then, the next time (shouldn't have to wait too long!) one of the Watchtowers goes into one of its foaming-at-the-mouth diatribes against "wicked apostates", you could mention, "hey that reminds me of what the Republicans did with McLellan's book...I wonder why the Watchtower doesn't make the effort to refute the specific arguments, rather than attack the motives, of its opposers?"