The problem here wasn't that they kept the engine running. I would have done the same (unless told different by the QRH)
You want to stick by the QRH/ECL? Fair enough, absolutely no argument from me, but dare I point out that in that case you
wouldn't have done the same as this crew because you would had actioned QRH/ECL fully and correctly, identified an engine fuel leak and shut the offending engine down in flight.
In short on the triple an Engine fuel leak = appropriate engine shutdown on the 777, there's no QRH option/ECL option to keep running at idle and land but not use reverse.