“It also might be on the Saudi peninsula, Pakistan, or an Indonesian island.”
Vey unlikely to have continued on to Pakistan or Saudi, there simply was not enough fuel to do that. Further the aircraft would have to cross Indian territory(Andaman & Nicobar) to do that. There is a very strong military presence there, being home to a large base especially meant to keep a close watch on the Malacca Straits. Chances of a large aircraft like this one getting close without detection would be extremely unlikely. More likely that the aircraft took a sharp turn southwards and went down there.
Soft landing. No crash. No ELT signal. Pilot walks away in somewhere like Afghanistan or Kasakhstan.