Yes, for those interested in this scenario, check Helios Airways Flight 522. I think that's what happened with MH370, except that the depressurization was deliberate. Most likely a single pilot stayed alive and functioning in the cockpit, eventually repressurizing the aircraft.

Perhaps the pilot's goal was to hide all the evidence as well as possible, to create a perfect mystery. Then a controlled ditching would make sense, although it kind of failed considering the debris which eventually reached Africa.