Cazatou,
As far as I'm concerned, no one is calling into question the service, or ability, of Air Vice Mashal Day (nor, for that matter, Air Chief Marshal Wratten).
What is being questioned is why they ignored the rule in place at the time - that of finding deceased aircrew guilty of negligence with absolutely no doubt whatsoever.
To answer your question to Ark Royal - "What would you do?", my own personal answer would be - I don't know, because no-one knows what was going on. In broad terms, I suppose would be trying to fly the aircraft.
May I also reassure you that us non-"superheroes" are fallible too!
My best, as always.
Brian
"Justice has no expiry date" - John Cook