You said your former Bible study Conductor (s) were good people so they most likely didn't have any ill intent in teaching you what they had come to know themselves. Treat them as you would like to be treated yourself. After all, when you were a JW you may have studied with someone or may have brought them some literature that influenced them greatly.
I've run into old JW friends who didn't realize I was no longer a JW and they start asking me about JW things in my area. I tell them that I realize that this won't come as good news to them, but being a JW just wasn't working for me any longer, so a number of years ago I stopped attending the meetings.
Sometimes they want to know why and I've told them, only to have everything I've said, promptly dismissed. Lately rather than explain anything to them and end up in some kind of debate that doesn't end well, I simply say:
Me: I discovered a few things I should have known before making the decision to be baptized as a JW.
Them: Oh....like what??
Me: Well, let's just leave it at that, but don't worry, I'm doing well. I'm still the same person as before only now I'm not one of Jehovah's Witnesses. How have you been...how's the family?
At that point they usually get the picture and since you're being polite or haven't said anything they can argue with, the ball ends up in their court. It's up to them to change the topic or wriggle their way out of the conversation.
Sometimes people want to be lied to and they are quite willing to punish anyone who doesn't play the game. I find it's better to leave them wondering rather than have them blame me for telling them something they already know, but have been successfully denying.
