Couple of questions, more general than specific as I really don't think there is any point speculating until more information comes through from AAIB:
1. If there was an issue with insufficient fuel getting to the engine would this not be flagged up by the FADEC as a fuel demand versus Acutal crosscheck failure?
I thought the FADEC would demand a certain amount fo fuel based on the TRA and command the FMU actuator to adjust accordingly. It would then monitor the fuel flow rate and based on that make adjustments to keep things as close to steady state as possible.
If the actual flow rate was significantly below demand then the FADEC should have declared a warning to the cockpit EICAS/MCDU.
2. What diameter are the fuel supply pipes? Some aircraft have a system which oversupplies fuel to the engine and then returns the excess to the tank. I think that part of the purpose of this is to keep the fuel flowing. Does anyone know anything more about this design?