It may be that the beacon was inop or failed to trigger for some reason, when it can be very hard to spot a wrecked aircraft in the thick tropical vegetation. Aircraft tend to go in through the upper canopy, making a rather small hole, and then lie hidden on the forest floor, according to what I have been told.
Absent an ELT signal it can take a very long time to find a crash site in the terrain found in that region. It varies between hilly, mountainous and thickly forested.
Usually these new ELTs are pretty good for location; we had one accidentally switched on when the Nigerian authorities came and got us within a short time, telling us which airplane it was and even where it was parked at Murtala Muhammed Airport! I was impressed.
I am sorry to hear about this recent accident after a long period of operating safely.
Jerry, ah! He was a real character, wasn't he? Just another guy spouting inconvenient truths who seems to have been shut up permanently, as with so many others there in Nigeria. Keep his memory green, Doctor.