My observations for what it's worth as a 20 year "veteran" of the Boeing 747(all types) are as follows:-
The aircraft and crew were JAA licensed and BA operate within the USA as FAR compliant.
Given the same circumstances, I would also have continued to destination, unless my crew (inc. cabin crew) and passengers expressed serious concerns, having observed the effects of the engine surge. Indeed, I have on 2 occasions cotinued the flight in similar circumstances - legally and safely.
My criticism of the crew would be this:- they were either naive or inexperienced on this particular routing, to assume that they would achieve every optimum altitude for maximum fuel-efficiency as the flight would cross the Atlantic on a random track against the NA track system at that time of day, when a lower than desired flight level is more often than not,only available;-
and, their knowledge and management of the fuel system was deficient.
Other than that, the flight was completed safely, albeit to an alternate and I think that The Boeing Aircraft Co. may be seeking urgent clarification from the FAA regarding their new 4-engined B747-8 and it's operation following an in-flight engine shutdown. If the non-normal QRH is to have "land at nearest suitable airfield) added following completion of the engine shutdown checklist then Boeing and Airbus may as well abandon their 4-engine production lines!
P.s. one doesn't "loose" an engine, one "loses" an engine.
As for 2-engine go-arounds, it has been possible since the early days of the 747-100, just more exciting then!