I find it sad with todays technology that the control centres along the route had no idea what was going on. I'm glad that I now operate in areas of good communication & radar coverage. There is no excuse......apart from penny pinching.
While it is indeed possible to extend radar coverage to every part of the globe, it's not cheap. Radars that are affordable to non-defense entities are not really powerful enough to stretch over those large bodies of water and you need to base them on land. Even then they're expensive to operate. The only radars really powerful enough to cover that much water would be extremely high power over the horizon radars from the cold war era. I don't think anything like that is really feasible for any country in South America or Africa. In essence, there was nothing along the route to communicate with.