If I remember rightly (and I may be wrong)
there was a case where a judge commented that a man being drunk, no matter how drunk, is no excuse for incorrectly thinking she was giving consent.
Basically when she is drunk in this situation she doesn't carry responsibility to ensure he is consenting ( to my knowledge ones never been convicted) whereas when he is drunk, no matter how drunk, he still carries responsibility ensure she is consenting.
I don't know if this led to case law.