let us keep the AAC on their pedestal for the moment
Well let's not. Although the investigation procedure is generally well conducted, just about every Lynx BOI since its introduction to service (and there have been too many) has recommended self-sealing fuel couplings, crash resistant fuel bladders and enhanced fire retardant measures.
In 30 years of crashes, not a single jot or iota has been done to effect this.
This, however, comes back to Tucumseh's territory rather than the AAC per se. The Support Authority (MoD) and the Design Authority (Yeovil's finest) can never quite find the funding, motivation or time to do any of this, so the Lynx still remains as "Most Imflammable Light Utility Helicopter in its Class." despite numerous BOI recommendations to the contrary.
My point? An effective BOI means doing something about the problem, not just neatly and accurately identifying it.