Folks,
Dogma is correct, and the intent of Annex 13 is clear.
The BALPA intervention as an interested part was entirely proper, I would have expected no less.
The Hunter pilot on the day had no criminal intent, no "mens rea", the guilty mind, effectively a prerequisite for criminal charges. If he made a mistake, it certainly would not have been intentional, who hasn't made a mistake flying, at some time or other.
Whether we like it or not, the "default" position of police is "crime and punishment", not aviation accident prevention, the intent of Annex 13 and complimentary British and EC law in aviation.
I can think of only one loss of an aircraft at an airshow in the UK where I would agree that there were strong suggestions of reckless and negligent behavior, that was the A-26 at Biggin Hill in the 1960s.
There was one epic case in NZ, included in the precedents in this UK High Court case, the NZ police were hell bent on locking up the tec. crew and throwing away the key, after the accident that occurred during the handling of a gear problem.
Even a member of Qantas senior management appeared as a witness for the defence, such was the Qantas view of the importance of keeping accident investigation data away from criminal or civil actions.
Had the NZ police won their court action, it would have had a chilling result for any aviation accident investigation in NZ, who is going to give evidence that is going to find them in the pokey.
In Australia, despite lip service to Annex 13, and a piece of legislation that apparently enacts Annex 13 data protection as Australian law, ATSB and CASA are all too cosy, pilots are very reluctant to say anything other than the absolute "name, rank and serial number" minimum to investigators, because of the propensity for such information to "leak" and "inform" CASA parallel investigations.
I would point out that at least some of those killed or injured were parked in an area with temporary parking restrictions, erected just for the duration of the airshow. Hindsight is always 20/20 perfect vision, pity the parking restrictions were not thoroughly enforced.