If they tried to return to the closest airport it does not make any sense to see these waypoints in the FMC. The 777 FMC has an Alternate airport function which at any time shows min 4 of the closest suitable airports. It takes 2 button pushes then to navigate directly to the selected airport via FMC which any B777 pilot would have used if on fire or any other emergency which warranted immediate landing.
ELT has an Off switch in cockpit.