This is a boy who casually expressed his intention to rape Luna Lovegood to someone he'd just met, assuming that boy's stated "intention" to murder her was equally casual, and equally serious. Major, major misogyny here.

I don't read that as misogyny. Merely a willingness to utterly humiliate a low status enemy by whatever means practical. If it was Larry Lovegood I expect the conversation would involve castration. Or perhaps sodomy via broomstick.