Typically, the one doing the penetrating is charged. Not always, there are cases of heterosexual rape where the woman is the aggressor. These posters are from a not-too-distant past where only men raped only women. If it was 2 guys, it was just weird gay stuff. Girl was the aggressor...guy should feel lucky. 2 girls; "nice."
I don't think these were legally binding posters. I'm not sure you'd get super far if even one person was drunk in court, unless they were literally blackout drunk and you had video evidence of it (or you were black of course).