Pings
What I understood about pings is that the trajectory arc is based on supposed speed and possible fuel range. Since the "handshake" received by Inmarsat means "engine still running", could it be possible the airplane landed somewhere within the arc and kept the engines running for 7 hours to make people think the airplane flew until fuel starvation?
From a ping we can only find the distance (angle) from the satellite. With a "handshake" is not possible to determine if the airplane is moving, or not.
Am I wrong?