PatriarchyPersonified, it's ridiculous to act as if being drunk is a binary condition, where you're either drunk or sober. There's a huge difference between having a few drinks and being paralytic.
It is perfectly possible for one mildly inebriated person to act in a predatory manner towards someone who is almost completely incapacitated, and the fact they're both drinking doesn't negate the assault. Sexual coercion, assault and rapes are not rare occurrences, and in nearly every case the perpetrator is male. I'm sorry if that offends anyone's sense that blame should be equally proportioned, and that every instance of male-to-female sexual assault should be balanced with an acknowledgement that, of course, female-to-male assaults do exist, but there's no real comparison. It happens a lot, and our culture has, until recently, regarded it with an amazing degree of complacency.
'You about to go run down some drunk chicks, all right? And don't confuse that with tipsy. We talking about drunk. I want vomit in the hair, bruised-up knees. A broken heel is a plus. That's what you want to find, okay? [...] All you doing is using your instinct. That's it. That's how a tiger know he got to tackle a gazelle. There's a code written in his DNA. It says, "Tackle the gazelle." Okay. And believe it or not, in every man, there's a code written that says: "Tackle drunk bitches."'
That dialogue is from a successful 2005 comedy. The speaker is the protagonist's player friend, written to get some laughs/eye-rolls with his cynicism/bravado/sleaziness, and highlight what a nice guy the main character is. The point of this scene is not to show how grotesque his attitude is; it's how the protagonist is trying out various approaches to meeting a woman.
I don't think dialogue like that would come out this year, at least not without comment, but it's a clear indication of how normalised the concept of targetting really, really drunk women is. And just because the speaker of those words would've had a few drinks themselves doesn't mean they're both drunk and all is equal.
None of this has any specific bearing on the OP's friend, but that's the greater context of his situation: a culture where deliberately making advances on women who've vomited on themselves, lost their friends, smeared their makeup, cried or mislaid their keys is a tactic common enough to be a joke, even a cliche.