For the airplane to have reached this position, whoever was at the controls at this time must have disabled the other well before, as it is utterly implausible

For the airplane to have reached this position, whoever was at the controls at this time must have disabled the other well before, as it is utterly implausible that the other pilot could have been persuaded to cooperate in the flight path to that point, and only slightly less plausible that the pilots conspired to follow that flight path. From these considerations, the other pilot must have been incapacitated at least by the time the airplane flew past Penang, a more-than-adequate airport for an emergency landing, and probably at or before the alleged emergency that started the events. As for the pilot's motives, if this holding pattern did occur, we can only speculate - and I, for one, can speculate that the pilot was balking at taking the final step that would lead to his death, but he was flying a planeload of people killed by his own hand...