A few weeks ago a 50+ year old bloke was climbing a route on the organ pipes called Battlements (3 or so pitches, grade 15) with his wife. When the going got too hard, he attempted to aid, then decided to bail. he was rapping off one nut backed up by a chockstone, apparently not equalised. the rap anchor failed – from the wife’s description it seems that the nut pulled then either the chockstone dislodged or the webbing around it somehow failed (it is uncertain from her description). he fell 20m to a ledge, then stood up disoriented and fell off the ledge to the ground some 30 or so metres below.
lesson = don’t be stingy when it comes to rap anchors. leave that extra piece.