Originally Posted by
Gysbreght
To understand that engine thrust is not required for control of airspeed and vertical speed at touchdown, have a look at these time histories from the A320 ditching in the Hudson river:
Bit of a difference between a controlled ditching in a river and... the Southern Indian Ocean, a thousand miles from land, with waves several metres tall.
I can't see any sane reason why someone who planned a controlled ditching there would have waited for the engines to run out of fuel first. That would dramatically reduce their chances of success.