Recorded data indicates that an adequate fuel quantity was on board the aircraft and that the autothrottle and engine control commands were performing as expected prior to, and after, the reduction in thrust.
I interpret this statement to mean the autothrottle and EEC output were correct, or as "expected".
This work includes a detailed analysis and examination of the complete fuel flow path from the aircraft tanks to the engine fuel nozzles.
I interpret this statement to mean that AAIB thinks the problem is a fuel flow problem of some kind.