@Downwind Lander.
All Hunters in the UK are currently grounded by the CAA withdrawing their permits to fly so there is no urgency to issue anything.
A recent appeal court decision in 2013 relating to a fatal in 2011 confirmed that AAIB reports are admissible as evidence in any court proceedings.
I think we can safely say that one way or another this accident will result in court cases.
So I would advise the pilot to say nothing whatsoever to either the AAIB or the police without professional legal representation....who of course may advise him to continue to say nothing whatsoever on a permanent basis.