I don't want to spoil it for you, but the 'Boney M' thing was when one of the climbers had been badly injured and the song 'Brown Girl in the Ring' kept playing through his head, after six days drinking snow as water and without food, when he was stuck on a glacier - which he hated (the song).
Watch the move, it's shot like a documentry, but it is just so gripping you won't turn the telly over. Even better, get the DVD and see the extras about what happened afterwards.
Ravs