Yes, I see what you are saying and we are probably in agreement, except perhaps to the degree of causation between "airworthiness issues" and any specific accident where a definitive cause is unobtainable. No biggy, I think, but as an example I suspect the Mull of Kintyre accident could be revisited by any number of "competent" bodies and the result would be the same "cause unknown". (BTW, was that not the finding of the original RAF Board?? Which was then overturned incorrectly by Wratten and Day? Happy to be corrected if I've got that wrong.)
Anyway, none of this was my original point anyway. I was merely alluding to the fact that all regulatory regimes will be flawed to a degree. The RAF/MOD one at the time of the MoK clearly was. Hopefully lessons have be learnt and applied. The FAA clearly has its issues. As for regulation and compliance within the CAA and EASA, I think that's a *****ing joke, as demonstrated by any number of recent high profile accidents. But I think maybe I've made my point and its time to move on.
Thanks for the discussion...seasons greetings one and all.