http://www.pprune.org/8277778-post7.html
The AAIB will be investigating not only the ultimate cause of the crash but other factors which may have contributed. It was a commercial flight so I suspect those investigations will include looking at (for example) the nature of the operation, management structure, flight ops structure, safety management systems in place (if any), procedure for authorising flights, and freelance pilots self-authorising if that is what happened in this instance.
They might even look at the risks inherent in a 'no fly-no pay' system, particularly when combined with self-authorisation, if that was the arrangement here.
Has the report filled in any gaps for you AoOOS ?