bose, I don't intend to get dragged into a detailed discussion here, but I do wish to respond to some of your points:
There is a major difference between the morality of the CFI's actions by encouraging the flight. But there still has been no evidence that the return flight was outside the control of the crew.
This does not make sense, unless you are suggesting that the CFI was content for the PA28, having arrived at its destination, to remain there. This most definitely was not the plan he had proposed to those involved, so I fear that the out and back legs come as a package, as it were.
There is way to much emotion and moral indignation being applied to this. Too many people emotionally raw trying to apportion blame.
Certainly not from me.
The fact still stands that the crew were responsible for the flight and did not make the right decisions.
They behaved as humans do, when subjected to motivation, presented with goals, and given guidance and encouragement by those they trust and respect. To my mind the difference here is that the dawning realisation of the horrible situation they were in, arrived just as the oppportunities to avoid it disappeared.
The AIB report indicates the same conclusions.
The AAIB have a remit limited by their own desire to delve; in this case, they clearly did not wish to publish more information than they did. I fear this is to the detriment of the flying community at Blackpoool, in particular, though we may note that they are not the only people investigating this event.
The ethical issues around other parties behavior does not change the facts.
The facts, as analysed by someone who wishes to understand why the occupants of the aircraft died, most definitely encompass the behaviour of those on the ground who arranged, commissioned, and advised, the pilots involved. It is this matter, that the coroner must pursue if he is to hold an effective inquest.