If a pimp threatens and intimidates a prostitute into having sex with someone and forces them to act like they are willing, are they not still being assaulted when the act of sex occurs? If an act of sex is assault, is the other person not assaulting?
Stallman comes across as discerning here because he's drawing a distinction between two things (sexually assaulting someone who is resisting vs sexually assaulting someone who is presenting as willing), but there is no real difference. The problem is not in his verbiage. The problem is that his underlying message is wrong.
He is trying to create a rationalization for why minsky's reputation should not be harmed. If Minsky flew to Epstein's private island and had sex with a very young girl of unknown age, his reputation should be harmed whether or not she "presented as willing."