I don't think we would have heard of it at all.

They may have witnesses he was at least at the party. Most people go to parties where they know a lot of people. If he and his buddies were being drunken asses all night, someone could remember that.

I remember a party where an older woman that was there "saved" a drunk girl that was in a bedroom with a guy. In that case, I actually think she broke up a consensual event, but it wasn't cool. They had no business sneaking into the hosts bedroom to go for it at least. She was the girls supervisor where they worked, so at least she made her wait and pick another night when she knew what she was doing.

I was there and was drunk, but was aware of all that going on. I could call a couple buddies and remind them, and they would probably remember it too. That was 30 years ago.