A not-helpful statement in the media:
"“I’m surprised it does not have a black box. Obviously, the black box is proved to be an extremely useful tool in aviation investigations and I don’t know if this plane was required to have a black box or not,” said James Hall, a former NTSB board chairman and current managing partner of Hall & Associates in Washington."
https://www.toledoblade.com/local/po...es/20190912111
I'll throw out some possibilities: load/CG shift or PIC medical event on final.