I spent the last few years repairing digital photos. The type of damage in your example can hardly ever be repaired. If entire image is distorted I can sometimes repair, this case NEF but I have repaired mostly CR2:

I sometimes say, as I have no education in this direction, if I can repair file with some patience, a known good file as a reference, a hex editor (I use HxD) and a RAW photo viewer (I use RawDigger as it seems very easy on partially corrupt files), then anyone can. Trick is to get the file 'working enough' to get RawDigger to accept it and then export RAW data as TIFF.
What works 9 out of 10 times is extract full res JPEG previews from either the corrupt files or straight from the memory card.
RAW files tend to be large, mostly the RAW image data. Chance that becomes corrupted is larger than the relatively small JPEG data becoming corrupt. Although tools exist that grab the preview JPEG from RAW photos, most of those I am aware of require the RAW file to be intact.
I made tool that also scans corrupt files for the JPEG (JPEG-Repair Toolkit) but a free trick I can think of is let PhotoRec think the RAW file is a disk image. Probably the free demo of DMDE can be used too.