Ven, I realize that having Jan as a exJW buddy makes it hard for you to come right out and say what you mean, and that is that is a jerk. If you did that (and you'd be right by the way) then regardless of how friendly you two have been in the past Jan would turn on you faster than the WT kicked him out of the org.
He is only your friend if you agree with him and do not make any negative remarks about his outrageous behavior. Does that sound familiar? Exactly. Jan is basically the exact same as the org. he left in terms of intolerance. You would be much better off speaking your mind about Jan the same way you do about the org. and then you'll see that there is no difference at all in terms of attitude.
Psychologically speaking, Jan is crying for help even though he is not actually aware of it. But it will not do him any good to cower to his verbal assault the way you do. Let him know how you really feel! Because he'll sure give you hell when you do and then you'll know how he really feels!
Mishnah