Have your heard of magnetic residue?
The problem with magnetic media (mechanical HDD) is that there is residual... Think of the residual as a "shadow" of what was once there. Left over magnetism. Although the average user can't find, or see, this residual, certain forensic software can see right through what is actually written to a sector, and recover data that has been overwritten. The "shadow" is eventually replaced with another "shadow"...
Chris, the drive is dead? It just gave out? lol