Ok, I'll bite.
Some of the speculation on here is just insane. We've had ridiculous, unfounded suggestions, including and Electro-Magnetic "weapon" fired at the aircraft, lightning etc, I'm only suprised Aliens haven't had fingers pointed at them yet....
It also seems people are either completely oblivious, or just ignoring the facts.
As far as I know the facts are.
1) The engines did NOT "stop", they just ceased to produce commanded thrust.
2) The aircraft did NOT run out of fuel (see 1)
3) Wx was NOT an issue
As for those "barrack-room" pilots criticising the pilot for not been stabilised at 1500ft
Ever heard of the 160 to 4 requirement at LHR ?
I'm not going to speculate anymore on this, applying Occams Razor to this is clearly a difficult exercise.