To those who suggested an engine failure and the crew shutting down the wrong engine.
First the B777 EICAS and company SOP's makes that pretty difficult, second no proffesional airline crew is going to do anything with an engine 600' above the ground on short final except continue the approach and deal with it on the ground.
For anyone suggesting that the crew had time to transfer control, troubleshoot the issue or generally do anything other than fly the aircraft obviously doesn't appreciate just how little time you'd have to recognize and respond to an abnormal situation that close to ground. The crew did exactly what they should have in that situation, jam the thrust forward, say WTF? and maintain level wings and do whatever you can to make the field without stalling the aircraft and making it worse.
Lastly they are not going to ground the worldwide fleet of B777's that have completed millions of trouble free hours for an incident that they don't even know the cause of yet. Should it be proven to be an aircraft/engine/software issue then i'm sure we'll see the AD come out fairly quickly.
In the meantime lets let the investigation team do their jobs and figure out what happened. Best thing you can do in the meantime is close your mouth and not make yourself look any stupider by coming up with outrageous theories on a subject many of you apparently know little about.