Cashill says the traffic-control equipment was sabotaged. Watch the video.
If the aircrew was following NOTAMs, they never would’ve flown in that place to begin with. Archaic traffic control equipment in Balkan countries are about as reliable as your cat bringing you firewood. As a pilot, you’d have to have rocks in your head the size of Gibraltar to trust it. Parts of the system kept being stolen by locals who were hungry enough to eat their socks, so technically, I guess it was sabotaged.