Would you mind also sharing the dng?
As for the NEF, it doesn’t surprise me that LR and PS can handle this damaged file. Adobe is big enough to devote some of his programmers to help fixing Nikon damaged files caused by Nikon.
On the other way, it doesn’t surprise me that none of the raw editors I tried could open the file (darktable, Rawtherapee, ART, Photoflow, Filmulator, Rawproc, Gimp), for obvious reasons.
What really surprises me is that someone from the FOSS world indeed lost some time fixing the damage, for free, and for a considerable number of cameras (unfortunately, not the model you have).
Just some thoughts to put things in perspective - as I see it.