Correct me if I am wrong; I did come across a bulletin a long time ago that the Boeing B777 QRH non-normals on fuel leak assumes an engine fuel leak if the leak rate exceeds 1000lbs per 30 minutes. As such one can possibly shut down a good engine when there is a leak from the tank ( assume no visual sighting of leak ) or from the fuel manifold prior to the spar valve.
Queries to Boeing receive an ambiguous and non definitive reply that the ECL and QRH procedures are sufficient to address all fuel leak scenarios. This has led to many to assume that leaks from fuel manifold before the spar valves or fuel tank leaks as improbable without visual detection. Sadly there are too many " ASS U ME " s here
