Have you got a link for that? I was reading a Barclays stockbroker investors magazine on my bosses desk this morning. It was doing some serious London property ramping and gave this as an example. "gottesman reportedly sold his home in kensington palace gardens for a record £115m, yet even at this sky high price the buyer seems to have the better end of the trade" it then goes on to say the buyer was Lakshmi Mittal. The mag was sent out this week so it seems they have convienently ignored the information which you posted.
Found one
http://www.thelondonmagazine.co.uk/Stories/Londons-most-expensive-street.html?PageNumber=2