Not the first C210 to have a wing breakup in flight. Check out the ATSB report on VH-DJT in 1976. The accident reports have a striking similarity and similar witness reports.
DJT was a strutless C210 while DBU was strutted but the outer wing panels could be very similar if not identical.
The propellor of DBU is in one bent piece and still at the crash site which suggests the ATSB do not consider it to be relevant to the accident or they would have taken it and the engine away with the wings, struts and carry though structures that they did take away.
Can't post the URL for the DJT report as PPrune says I have not made enough posts to do that??
Perhaps someone else could do that?