Pitching the nose up rapidly can make it extremely difficult for passengers to get to cabin. Taking it to 45,000 ft. for only a few minutes can kill the passengers from depressurization.
My tinfoil hat theory.
With Russia in Crimea, Obama wanted to send a message to China. One of our laser weapons that is classified shot out the planes electronics. The plane simpky shut down and nosedived into the sea. That’s why the cell phones stopped working.
Go ahead China, make a move. We will destroy the electronics on every weapon you own.