Clark Lindsey has the press release from Scaled about last summer’s fatal accident. Short version, by my reading: we still don’t know what happened and probably never will, so we’re just going to be a lot more careful in the future.
I still think that they continue to overestimate the safety of hybrids, and that it wasn’t a great choice for propulsion. I suspect that if Burt were starting from scratch now, he’d go with a liquid, but shifting to one at this stage would involve too large of a redesign of the airframe.