A double engine failure would have led to a drastic reduction in rotorspeed-especially considering that the pilots are very inexperienced.
Just a few days before, the Kenyans had sent the factory pilot home, as they considered their own pilots (according to reports each of one had less than 1000 hours total time) good enough to fly it.
It is not unlikely in this culture to run out of fuel......which would explain an engine failure.....but i still believe that it was VRS.....all it takes is a slight RoD....Kenya is at 10.000 ft PA, and sometimes even higher....