It's frustrating and hard to find real information regarding what he did say and what he did not say, so I feel I shouldn't play the judge here. I did find this direct quote of him on his website, and it doesn't sound to me, from reading this piece, that he was trying to defend Minsky:

> Headlines say that I defended Epstein. Nothing could be further from the truth. I've called him a "serial rapist", and said he deserved to be imprisoned.

https://stallman.org/archives/2019-jul-oct.html#14_September...

I do not think this changes everything, but if this is indeed his honest opinion, then I do feel that he might have simply communicated his opinions very poorly.