I am sorry Old Duffer but I strongly disagree with your last.
Sir John Day may well have received poor advice from a DLS Sqn Ldr with no knowledge of AP 3207, but in a matter as important as this he should have sought further clarification.
Air Commodore Hine, author of the "No doubt whatsoever" requirement was available.
Air Commodore Peacock-Edwards the "then", Inspector of Flight Safety told Wratten and Day that the verdict was not justified by the facts.
They have had seventeen years to right this wrong.
Sorry, I am ashamed to have served with these Officers