Mr B,
Yes, it is fairly damning (understatement of the month) but I'm not sure it implies crticism of the RAF flight safety system (ie IFS) per se, as I don't think IFS were responsible for SFI/AIL/ANA promulgation and monitoring. That was more the remit of Handling Sqn Boscombe Down who would send out SFIs to the world in a signal using an AIG. Action addressees (Gp tasking & op staffs/sqns/TPs etc - I would think) would be required to ack receipt (anyone know if that included IFS (RW) and Gp FS staff? I can't believe it didn't!).
Its likley that ANAs, AILs and ALs would be similar in origin but the releasing authority would probably be the relevant ProjO within DHP of MoD PE. So, IFS should have known - but responsibilty lay with MoD PE -even then, there was only so much that Handling Sqn/ProjO could do to check disemination.
Of course, the way these changes were seen by the crews was by the use of the 'reds/greens' signature cards on Sqn Ops Desks and checked at every crew out-brief. I often remember turning the aircrew signature cards to 'red' on receipt of ALs to FRCs, Aircrew Manuals or ODMs and, more occasionally, when ANAs & AILs hit my desk.
Ultimately, this is not about the fact the SFI(s) existed but that the BoI neither realised its signifigance nor investigated/commented further. Subsequently, this knowledge has almost been denied by MoD and their airships - especially when S/L Burke referred to UFCMs as a possible cause - one that would leave no evidence.
Damning of the RAF Flight Safety system? - Not massively.
Damning of the MoD's airworthiness process? - Most Definitely!
(It is also precisely what Mr Haddon-Cave found)