It didn't land there, just continued it's turn before entering a hold near Bristol then proceeded to land at LHR. You can tell using the colour of the contour line. Just odd that it didn't divert to SNN, DUB or MAN.
As we don't know what the reason for the return was, that's up in the air, as it were...... It's much easier to get passengers on a flight from LHR than it would be from any of these airports if the aircraft is tech.