SoCal - I don't accept that "indicates a somewhat cavalier attitude to the safety regime imposed by the Civil Aviation Authority" is necessarily true. It might indicate all sorts of things. Lazy at paperwork? CAA phobia? Dyslexia?! He could have been superbly competent for all we know. My first point is that you can prove you are technically safe with a test, but having a piece of paper that says you're safe to fly, doesn't make you safe to fly! It doesn't prevent an irresponsible attitude.
According to the video evidence, CM did another A check before that short last flight. So, my second point is that he thought he was being conscientious. He thought he was flying within limits. He was wrong - and it was that lack of judgement that cost the senseless waste of three innocent lives.