@Hebog
The AAIB published a special bulletin in September.
In it they stated that the aircraft appeared to be responding normally to the control inputs from the pilot and no abnormalities have been identified.
They also described the interior cameras recording and gave the speed and altitude at the top of the inverted position.
This is why @Piltdownman made their observations about the lack any apparent failings in the aircraft itself.
The exact phraseology of the AAIB is on page 5 of the pdf link from from this url below
https://www.gov.uk/aaib-reports/aaib...nter-t7-g-bxfi