These two sentences do not contradict each other, because rape culture is not the same as rape. Modesty is not rape, but modesty culture is rape culture because there is a causal connection between the taboos of modesty culture and the alleged justifiablity of rape. This network of causal connections between modesty taboos and the acceptability of rape is what this author means by saying that modesty culture is rape culture.

This is a valid and profound point which by your own admission you have no quarrel with. Your insistence on splitting logical hairs, when you have no significant disagreement with her, is more than a little obnoxious.