As far as I know Minsky declined to have sex with her. Yes, he was stupid to associate with a convicted rapist, but he was at least smart enough to not have sex with girls accompanying the rapist. Not a high bar, but still a bar he cleared.
At the time Epstein was not a convicted rapist. However he certainly was a shady character and it is likely Minsky had every opportunity to distance himself from him. But he did not.