So he friended you....
I think your account of the friendship can be spoken of, how much you appreciated all he did for you and that you love him for his caring and protectiveness. He seems to be the kind not to be afraid of anything and use all in his power to overcome what seems like insurmountable obstacles, using the powers that be in his favor to get justice rather than just letting it be taken care of by those in the congregation who should be caring for your life and soul. For all the words spoken of off the platform, rarely do you see such enthusiasm or caring actually acted upon.
If nothing else comes of it, at least he will know your true feelings and that he is one person who you admire trememdously. Because, as you well know, once it is said you have left the truth and he and his wife are still in, its a slippery slope from there on down. But no matter what comes of it, at least he will know your gratitude in standing up for you when others did not.... he may come back to you and with all your knowledge and quick wit, being quite a master of language and start asking questions himself... you never know...
Just my 2 cents