That's fascinating, I've never heard of hard drive data recovery using liquid nitrogen. Is the idea that the lower temperature prevents the drive from overheating long enough to recover the data? Sounds very cool.
By freezing the drive, the metal would shrink just enough to unstick the head. Of course the location where the head crash had happened would be corrupt, but the rest of the data would be fine (mostly).
I spent 40 minutes copying that drive, got every bit back.
Boss asks, “What are you doing?”
“I’m milking the data out of this drive!” ;)