Yes, I know that. That should have been one of the first places the authorities should have searched.
I would be very surprised with all of the SAR assets used that they would have missed it the first time.
Seas are very big places, and sometimes things happen you don’t account for. Plane ditching in the water, disappearing under then the pieces getting temporarily buried, then resurfacing after breaking free, etc. Not to mention it’s just plain difficult to search vast stretches of emptiness.