R I Howard. There will always be aircraft accidents where the cause can not be stated with 100% certainty and this is true of the Wittering crash. The inquiry will then examine all the facts they have available and come out with the most likely cause. The facts point most strongly to indicate the aircraft was allowed to lose flying speed and subsequently stalled at too low a level to allow recovery. There was no indication of structural failure and the speed and attitude would not have placed undue stress on the airframe. The situation shows a possibility of classic "Distraction" where a relatively minor incident takes over as the main priority and attention is lost on flying the aircraft, sadly not an uncommon occurrence.
This may not be the opinion you want to hear but I think you should consider it the most likely explanation of the crash.