I just got through reading your thread, and haven't had a chance to read the others comments. So this may have already been covered. But when you are a faithful JW, it has been pounded into your head to reject anything that smacks of "apostacy". Certainly if the person comes right out and tells you where they got the info. (ex: the internet) it automatically puts up a wall between you and the person you are trying to reach. At times it may be appropriate to do what you have suggested. But for sure, there are many times that call for much more caution. And this is true even when you are speaking with the elders. Many of those once serving left because of what they have found out too. If their hearts are right, and their hearts are ready, God will draw them out, no matter what their position. So, some want to try and reason with even them at their judicial meetings.
However..for those of us who are trying to reach the hearts and minds of our brain dead loved ones and friends still in, the subtle approach is much more effective. 9 out of 10 times, the messenger is always attacked by those who are told the facts. Not the message. That being the case, it is wise on the part of the person who is trying to reach the heart of another to reason with them. Blasting them with everything at once, including where the info. came from will only back them into a corner, and the wall of reason will go up. JWs are scared to death of "apostates". They are told they only want to destroy your faith and have nothing to offer you. (They know nothing of freedom of conscience.) That is how fear keeps most from examining anything we have to show them.
My own personal experience is that in which my parents who raised me in the organization, started having questions on the whole blood issue, when my mothers father, also a witness, died for refusing blood. For my father, it was that, and the whole molestation issue. They started fading and in time I thought of them as being very spiritually weak. One day they came to me with some of their findings, and told me why they would not be attending anymore. I was devistated. Because they were even considering leaving, coupled with the fact they were bringing to my attention many issues that I had never heard of before, I closed mindedly concluded for two years, that they had gotten into apostate literature on the internet. Although I had no proof.
It was true, like you said, many, found the info. on the internet and then checked it out for themselves. But it is a good thing they did not tell me that, even though I suspected it. Had they, I may have put up a even higher wall and perhaps may have been even more determined never to fall into their trap..as I then viewed it. You see I knew my parents were good people, and would never leave Jehovah and Jesus on purpose. (That what you believe when a JW leaves, you cannot have a relationship with them without the organization.) I wanted to believe they may come back, and that there was still hope for them. Had they out and out told me where they got their info. like you are suggesting, I would have dug my heals in more, and attacked the messenger, rather then the message.
Of course, not all situations call for such reasoning. But I know there are many out there that feel a softer more gentle approach will get them further in trying to help get their loved ones out.
Remember the scripture: "..therefore prove yourselves cautious as serpents and yet innocent as doves."-Matt. 10:16