It was well known shortly after the incident (one or two months) that the pilot had taken complex maneuvers that would explicitly avoid radar detection around t

It was well known shortly after the incident (one or two months) that the pilot had taken complex maneuvers that would explicitly avoid radar detection around the Malacca Straight. This was done very soon after the pilot disabled the plane's transponder. At that point it was clear that the pilot had carefully planned to commandeer the plane.