Stable= Gear and land flap down, approach power set and speed no more that touchdown speed +15kts. I can tell you for a fact they were stable. And I mean fact.
So if they were stable, with approach power set one can assume that the autothrottle wasn't asking for
that much power when the engines failed to respond, surely they must have had considerably less than 'approach power' on for this to happen...unless of course the engines actually lost power (which the AAIB didn't mention). What sort of N1 would a 777 have on for an approach like that?
Sorry You Gimboid you beat me to it!