Kiwi
Indeed, a lot to learn. As eharding (who should check some profiles before suggesting people have "sod-all hours") might consider, no-one is going to learn anything if we don't discuss the issue. A and C has clearly learnt what I think is the most important lesson - we instructors are all imperfect, and there is always value in pointing our students to other sources of learning.
Flying for Fun (and englishal, who brings up HP&L)
There is also risky shift to consider. A group of people will often take decisions that are less cautious than any one member of the group would make. Everyone thinks it is OK if no-one else has raised any objection. This whole exercise was a committee decision, that had actually been made by the time the aircraft commander had arrived.
Then we consider authority gradient (like cockpit gradient, but some decisions made outside the cockpit and considering other people than crew). This is an inexperienced pilot - about 40 hours on his PPL. He is given a decision, as a fait accompli, by more experienced pilots. He doesn't make a decision to go (or indeed not to refuel in Exeter). He simply does not question decisions already made, which should rightly have been made by him. All (f)ATPLs know the dangers of steep cockpit gradient, but have also been taught the dangers of flat, or reversed cockpit gradient, when a weak, inexperienced commander flies with assertive, experienced crew. They were not crew, but did act like they were!
The club also gave him something I constantly work with my fine ops staff to make sure my crews are not given - an unworkable plan. There was no way he could get back safely before nightfall, when his flying privileges no longer apply. The flight could not be completed in the time available before nightfall. He could fly the sectors, but did not have time to refuel. Fuelling at Exeter is reasonably swift, but with only one pump, and that on the South side (note they went to the North) would have delayed their return beyond nightfall.