Nor does it excuse a descent to mob justice (from either side).
Our law is based on procedural justice because it turns out that societies run on mob justice are fucking terrible.
Basically - I'm on this tangent because I find your line of reasoning distasteful. The answer right now is that we don't know.
Unlike both you and those you disagree with, I don't think it's appropriate to make any judgement on this from our armchairs on the internet.
At best, we're in the "trust, but verify" stage of this with regards to a single accusation with no confirmed time or location (or any other detail, as far as I'm aware) - Yet I see a whole lot of folks happy to be judge, jury, and executioner (again, on both sides). With basically no one suggesting that maybe we should do our due diligence first.
He might be dead, but his wife isn't, his friends aren't, his memory isn't. And while I sure agree that RMS is one tonedeaf motherfucker, I have at least some empathy for the impulse to defend a close friend (although lord knows I wouldn't have gone about it the same way...). Particularly given it happened when the friend wasn't around to defend himself.
Now - having said that, I chose to comment here because while I fault both sides for jumping to conclusions, I find it MUCH more ethically troubling to jump to a conclusion of guilt. Mobs don't lynch people they've decided are innocent, they lynch the ones they've decided are guilty. I judge that much more harshly.