Norwegian newspaper Dagbladet now reports that rader observations showed the aircraft descending, then climbing before radar contact was lost. Also, the a/c was supposedly on the south side of the tall mountain range Kebnekaise, as opposed to on the north side as expected. There is speculation that the a/c was off course and might have been flying less then 200 AGL.
The information is from the Swedish leader of the rescue operation, himself a pilot. If this is correct its hard not to think CFIT.