Maybe the intention of whoever was in control of that flight was...

Maybe the intention of whoever was in control of that flight was to fool any tracking / intercept attempts by going (electronically) silent, radically change course from where everyone would be looking for the 'missing' plane to mount some sort of surprise sneak attack from over the Indian Ocean (ie an attack from the rear).

Just a possibility...that may have come unstuck by limited flight training (especially navigating at night) or some action by the passengers / crew.