I think they replaced her hard drive with one from another computer that was crashed before they handed it over to the techs.
The techs could then testify that they found the drive was damaged, but recovering the data would have revealed that it wasn't her hard drive.
Once you take the cover off a HD, it pretty much done. I suspect the "scratch" is a bad section of the HD where the head crashed into the platter. Many laptops have motion detectors in them that idle the HD when subtle movement is detected. A quick sharp blow would be detected, but not in time to prevent "some" damage.