A shootdown ?
What target do you go in search of in darkness and at 2 am ?
Any hi-jackers may have done just a little planning I would have thought.
If that would be a serious option perhaps closer to the end of the flight would make a statement and be some form of possibility, certainly as far as seeing a potential target goes.
I don't see anything that suggests the aircraft has been taken over.
After 3 or 4 days I also doubt very much that the media, and us, are getting told anything like the real facts. This certainly is a strange one and I feel for the friends and relatives.