Scoobydroo#534 writes the editor of the Scottish Sun was on his phone when he heard the helicopter in trouble. I am not sure if reading between the lines that means he managed to record some of the descent, so the authorities had some idea what happened right away.
If the pilot had some power ("engine making noises") he would have been aiming for a better space than an intersection.
(1) If you have some power to make a controlled descent, but that is lost at say 300ft agl, would you be able to initiate autorotation?
(2) Is the ATC record from the transponder as accurate as a record from an on-board GPS? I am wondering if the description "vertical" would still allow a significant horizontal vector.