In reply to higherclimbingwales:
> this is precisely what doesn't happen because the people who have these incidents probably don't have the knowledge of their own abilities required to make these decisions
Yes, I see that the Dunning -Kruger effect is an attractive concept. But I was drawing attention to the impact on decision making of having a car down below.
On the way up, the walker will have made thousands of choices of route- most with a degree of uncertainty, particularly as the route is rather like a maze-comprised of a series of rolling 'pitches' limited by barriers to the line of sight, and they won't see the summit 'til virtually on it, Some route choices might incur a minor slip or a downclimb, a momentary feeling of being lost etc. They may not be choices made rationally, but even the most foolhardy will have greater awareness of their surroundings than when they set off.
The D-K effect seems to suggest that the 'victims' don't make the right decisions (on descent) because they overreach themselves. I wondered if the knowledge of their car's presence nearby ( a 'propinquity effect) 'draws them to attempt a beeline to it. Over and above mere chance, this might help to explain why some apparently experienced hillgoers risk benightment on the North Ridge rather than choose a safer alternative descent.
I'd go so far as to suggest that, were there a bus stop below Milestone Buttress, and it was getting dark, with the same time pressures, those intent on travelling home by bus would be less inclined to straightline it to their intended transport than the car bound.
I gave the example of Pen yr Ole Wen as another mountain this seems to happen on. Maybe the presence of the car induces an inflexible way of thinking. They could walk easily and safely off Pen-yr Ole Wen to Bethesda in the dark and then get a taxi to their car. but, like a driver who, when lost, spends ages looking at the map, rather than winding the window down to ask a stranger for directions.