"Social justice requires not just that individuals are treated as political equals, but also that their cultural beliefs are given equal recognition and respect. The avoidance of cultural pain has, therefore, come to be regarded as more important than the abstract right to freedom of expression."

The avoidance of cultural pain? More like the preservation of cultural hegemony. Tit for tat, here, would be for those whose cultural sentiments have been offended (by someone else's exercise of free expression), to use their powers of expression to ridicule, with some level of critical competency, the idea of a right to freedom regarding expression. Somehow, I do not think that such, even if they managed to accomplish it, would satisfy them.