Yep, I'm with 42psi given the information you have in the question, I'd go for answer 2.
For a start you have had a emergency diversion and a company response is required. Your managers and directors must know what has happened in order to formulate a press statement and perhaps decide to initiate a company emergency response; further, just because the airplane has landed safely you don't know, yet, if there was any trauma for the passengers which might require a company response and have the potential to expose the business to litagation. In this day and age you can expect a video on You Tube within hours of the event in flight.
Often information in the early stages of an emergency (even if the airplane has landed) is incomplete, even if you have spoken with the Captain who has called you as soon he resonably could have which of course his is required to do, he may or may not have had time to debrief the cabin crew and evaluate the passengers condition.
Flight ops and engineering may wish to download QAR and FDR/CVR data, so all in all the flight dispatcher/FOO on duty has a responsibility to initiate company alerting, in my opinion anyway. A report to the NTSB/FAA will be required and a timely call to your POI.
Just because the airplane has landed safety, remember that your problems may not be over- in fact they may just be starting. Your (the airline's) concern now is to focus on your passengers & crew welfare, the press/media and disruption recovery.
Last edited by no sig; 7th Sep 2008 at 11:53.