Something weird is going on in Japan, Korea and China.
I do not believe it is a coincidence any longer. That makes about 5 or 6 mysterious panel failures from aircraft entering or departing Japan in the space of 2-3 months.
Maintenance staff in one of these countries is causing these problems. It could be incompetence, lack of training or malice, but something is happening to cause these panels to fall so frequently. Investigation ought to be mandatory. The Japanese government is dragging its feet as usual. Sloth. Sooner or later a panel is going to find its way into the wing or a stabilizer and kill the entire aircraft.
Whatever is causing this needs to be found pronto.