Final report is out. In short, operating in turbulence above Va, encountered low-G, didn't apply aft cyclic to reload the rotor prior to countering an uncommanded rapid right roll and broke up less than 4 seconds after encountering the low-G condition.
The ATSB looks to be quite happy about the factory-fitted camera & data recorder though. Gives them a birds-eye view of exactly what happened, though it'd be sobering viewing for the investigators.