Thruthseeker;
You are right in a lot of areas.
I was 15 when Neil Williams died, he and my grandfather were well acquainted, Gramps always reckoned Neil was an outstanding pilot and good bloke with a poor grasp of risk. They had both been through ETPS at different times, and from what I saw regularly argued about pushing limits, but even Gramps was very shocked by what happened. As you say, accidents happen, I've had one, fortunately caused by multiple mechanical failures.
Go back through this thread. Look at "common purpose", There was no "common purpose"
This was an N registered aircraft, it should not have been doing what it was doing and DI should not have been flying it on that task or in those conditions. If there was no reward there was no pressure to fly outside his qualifications and ability, because if there was no reward it was being flown for pleasure and experience, therefore no pressure to get to Cardiff that night at all.
And it may not be the paperwork that makes the person, BUT the paperwork can at least help protect the innocent, and the AOC training standards are laid down, you either meet them or you fail.
Two men have died utterly unnecessarily, two families are suffering as a result, but the final decision to fly always rests with the pilot, be he 100 hr ppl or 20 000hr ATPL TRE/IRE, and taking off knowing that the weather is beyond your limits, or you are out of currency, or you are unfamiliar with the aircraft, or you're being pressured because its not a jolly, but a planned, paid charter is not accidental, it is a decision not taken lightly, but usually with due consideration. When that decision is made it is not an accident, it may have been pressured, but it is still the decision of the pilot in command, and his ultimate responsibility. DI will have known the status of his qualifications, and recency, he posted about it on facebook, he will have known how happy he was in the aircraft and how confident he was with it. No matter what threats, cajoling, or promises came from either the McKays or D Henderson he could have said no.
SND