"Stansted Radar missed it at the time of the occurence"
I find that statement quite amazing. They (and Essex Radar) seem to be very able to pick up instantly on an apparent +/-10 knot change in speed or to point out that the latest ATIS is "Lima" when "Kilo" is still being broadcast.
Are you trying to tell me that they failed to spot a B747 about to spear into the ground 6 miles out?
As a Stansted user I find this quite frightening.