I am not convinced that the man has a genuine case against his female boss, and I am inclined to agree that this is yet another case of political correctness gone mad.
The difference lies in years of women being paid less for the same work, and for for limited opportunities for advancement. In this context, patting a female colleague's bottom can be misconstrued in a number of ways that are not true if the roles are reversed.
Just my two cents worth
The Gods are just, and of our pleasant vices
Make instruments to plague us