This is the way I understand it;
Transponders can be turned off/on in the cockpit.
ELTS have 3 settings on, off and test.
Once an ELT is activated by "G" forces or saltwater, the only way to deactivate is to remove the batteries.
Yeh, they are talking about that on (Piers Morgan) right now. The fact that the ELT never activated implies it never crashed onto land or into water. Even Bill Nye the Science Guy is on CNN speculating.