I think you're absolutely right - certainly a Mil Mi-26. Not too many 8-bladed choppers to choose from! From its colour, it may well be one of the Mi-26 aircraft seconded to the UN, perhaps even this one seen at Entebbe Airport:
The photo dates from 2003 and the GE imagery you've placemarked is 2006. It may have been in support of the UNHCR in Rwanda and/or Burundi. Kasese airport is pretty rudimentary, but it's probably the nearest one to Rwanda, 100 miles or so to the south.