It seems this rumor is more fact than rumor. I think it is a tragedy. Oskar has been one of the more communicative Lindens.
So, what hard evidence do we have? The best I have seen is from Jessica Lyon, the lead in the Firefox Development Team. While I often disagree with her take on facts, I’ve never seen her get the basic facts wrong. She made a statement Saturday on the SLUniverse forum. See post: #21.
In this post she avoids characterizing the information. She does voice her feelings regarding the drama surrounding the information.
There is a post in the thread #62 that is supposedly from Oskar. If that is his post, then it is the authoritative statement on what happened.
There really is very little information on what happened. I will miss Oskar.