Flying the Atlantic with only 3 engines operating
These days I suspect that most a/c crossing the pond only have
2 operating.
As for the fuel emergency, it's possible that the pilots found that the fuel in the tank associated with the shutdown engine was not feeding to the other engines; i.e. the other tanks were running down to uncomfortable levels while the dead engine tank still had lots.
This seems to be the second recent example of an automated fuel system that suddenly seemed unable to get all the fuel to the engines:
Anybody got a towbar?