uk_ex_jw
In answer to your question about the others who are giving him problems. Perhaps some of the 'brothers' and 'sisters' are being nasty to him about his questioning.
Previous to this, he was most likely being love-bombed. Maybe friends have already started to ignore him, as he is showing signs of 'spiritual weakness', and he is no longer invited to social events, or welcome to drop by their homes and visit.
That can be very hurtful, and there's nothing wrong with telling him you are sorry that he has been so disillusioned, but felt it was your responsibility as a friend to warn him of the realities concerning the WTBTS TM .
Have you communicated with him since? It may be a good thing to let him know you told him these things because you care, and that you support him on his search for truth. You did not, and do not, want to see him duped by the org, and that is why you gave him the questions.
I don't know if you are a 'believer', agnostic or atheist, but it's not important that he sees things your way. He needs a friend, and one who cares about him just for who he is right now.
tal