If it had detonated in mid-air wouldn’t the black box (usually carried in the tail of the aircraft I think) have been found someplace other than 8 feet down at the point of impact?
Maybe. Or maybe not.
Depends on the size of bomb, where it went off, where the box is located (no clue in this plane), etc.
Too many factors and unknowns to conclude anything.
Pretty sure the flight and data recorders are securely mounted in the rear of the plane. To minimize material smashing into it from behind/crushing it. So it would tend to wind up near the top of the debris and crater.