This report turned out to be untrue but it also points out that so far deliberate action by a hijacker conforms to what is known and that flying low allows a pre - planned landing almost anywhere within a few hundred miles. The simplest action would still be a powered dive into the ocean after the cockpit was taken over. this would certainly minimize the debris halo.
Earlier this morning we had this.
Still missing but definitely elsewhere and flying low to avoid detection? That surely means that the pilot flying this bird does know what he is doing. The sudden direction changes detected at the beginning of the event looks like an attempt to dump altitude quickly without establishing exit direction. It obviously worked.