There seems to be a relative consensus that the initial 90 degree turn to the left could have been to clear traffic while initiating an emergency decent. However, that would leave the aircraft heading away from the airport. Assuming a fire/smoke, and possibly a resultant loss of comms, they would have wanted to land as soon as possible. Could they have initiated a right turn in an attempt to return to their original heading, but been overcome mid-turn and thus the 360?