The combination of your AH and FB or any social forum is lethal. You can expect these type of comments and possibly even more upsetting ones to freely flow WHILE HE IS A FRIEND there. De-friend him and he can sit in the toot and print words on toilet paper as far as you are concerned....because you won't see any of his rubbish.
He is a thorn in your foot and will continue hurting you until...YOU remove that thorn.
Whether that will upset or anger him is beside the point, as it is't his comfort and peace to worry about, it is yours.
Do yourself a big favour and give him the boot off your bit of FB, and really do go NC with him.
Good luck and peace.