Why is the memory unit fastened outside the chassis (storage box)? Surely, there must be a design rationale for doing this.
I assume the same design for the CVR as well.
So we have a description of a tail section supposedly sufficiently intact that the recorders are first thought to be inside that section. Now, there is at least one recorder that apparently separated on impact, and the impact forces also dislodged the memory module from its external mounting.
Only saving grace at this point is that the plane settled on a flat plain, and not on the slope of a crevasse.