Strikes me - and I may be very naive - that the nice thing about flying a helicopter is that you can 'stop' and hang around in one place for a bit while you contact ATC / wait thirty seconds for mist to clear / check a map. Or is there a fuel penalty for hovering? Increased workload when holding station? Is it just not done to hover in a lane?
I'm still puzzled as to why the a/c seems to have been approaching from the east -when the original flightpath must surely have taken it well to the west of London - and why the pilot did not contact Battersea control. If he didn't have time to communicate, suggests he was too busy aviating?