Forgive my ignorance but...
Could they be sure that "the fuel in the main tank associated with the shutdown engine" wasn't the cause of the shutdown?
Given that all the fuels come from the same source and the fuel for engine two migt well be coming from tank 3 depending on the pump pressure then I would say they could be very confident the fuel wasn't the cause of the shutdown.
Some of the real world pilots here have such a condescending, impertinent way of speaking and such an over-self-confidence that I would not like to have them as pilots on a flight I am on.
Over-self-confidence? No, we simply are the only ones on here who are aware of the design, operation and capabilities of the 744 and don't suffer fools who understand none of those things but consider themselves somehow to be experts. Perhaps the important term was 'real world pilots', instead of the pretend pilots spouting garbage on here.
If this BA flight had to declare an emergency, this alone proves that safety was compromised by continuing the flight
Sadly thats total b*****s and merely serves to demonstrate your lack of understanding of jet aircraft or the rules of the air. Perhaps you are the kind of person who insists on a full run down of how your surgeon will perform an operation and make misguided suggestions as to how you think it should be done better? You are entitled to your opinion, but that doesn't mean it's in any way factually correct. Which it isn't.