It's part of Regulation 13(9), but the subsection actually ends with: ".......... unless a Court or tribunal, having regard to the factors mentioned in regulation 12(5)(b) or (c), determines otherwise."
As an aviator, I have misgivings about AAIB reports being used in litigation - whether criminal or civil.
I resist the temptation to comment upon the role of the AAIB in the prosecution being discussed except to say, again as an aviator, that I consider it was an extremely worrying step in the wrong direction by a body for which, for decades, I have had enormous respect.