" The 'favourite' explanations seem to be either wind-shear or some sort of complete power loss on short final. "
Is there ANY history of serious wind shear at Heathrow ?
" this was simply a cocked up approach...similar to a particular MD11 in Hong Kong a few years ago...loss of airspeed followed by a high sink rate prior to touch down...in windy conditions "
Those WINDY CONDITIONS you refers to (China Airlines wasn't it - again ? )were a damn storm. The weather at Heathrow was nothing unusual. British weather is really quite mild generally.