I wouldn't be surprised if they were alive and smuggled out of the country on Russian ships. A death Certificate is the best way to live a happy life somewhere else without being worried about being dragged to an international court and having all your money taken away from you. They probably said they were dead, got smuggled out, and they are planning on doing the same for others. Assad didn't probably do it this time thinking he would practice on these two first. They aren't stupid, they know they are going down, they saw what happened to Ghaddafi and Mubarak, they were just buying time to get all their money and wealth to somewhere prior to finding a way to get out. Call me crazy but this is just a thought.
Remand of Meir Ettinger, Israel's most wanted Jewish terror suspect, extended (Haaretz)