• Best Scenario: They are wrecked with survivors on some island (unlikely)
• Stand Down Scenario: The plane crashed in the Indian Ocean
• Worst Case Scenario: Air Piracy or Terrorist refitting.

I would dismiss any Iranian government involvement -- they have plenty of their own planes ... For all we know the Iranians using false passports were refugees, defectors or the like.

Iranian involvement just doesn't make sense.

Hostage taking for some political reason might be a possibility.