Surely it still has 'thrust redundancy', as many of those that fly the 747 have testified that it is more than capable of flying on two engines. If, and I am sure they did, the crew looked at 2 engine driftdown, terrain clearance and available enroute alternates, I still think the crew were well placed to bring the aircraft home. At the end of the day, passengers may vote with their feet but this aircraft was operated legally and with the full support of BAs operation & flight planning back up.
Passengers may be able to voice their opinion on ETOPS. I would still far rather be sitting on the ocean on a 4 engine aircraft that has lost one engine than a 2 engined aircraft that has lost one. Which has 'thrust redundancy' then?
Hope all well Beagle.