Your friend is only half knowledgeable. It is true that riding coats, either for hunt or show, are cut so that all the buttons can be buttoned. But it is not true that they have two buttons. They are almost always three-button coats and sometimes even four. In theory, there is no different between hunt coats for men and hunt coats for women. In practice, men's hunt coats are single vented while, for purely aesthetic reasons, women's are double vented.