[...] the drive I was copying to is now left with 0% free space, which means the bad file copied was bloated which is why the HD light remains flickering.
No, in all likelyhood that's not the explanation. I assume you are using FFS as filesystem, not SFS/PFS or anything like that? In that case, you are probably seeing FFS' built-in diskvalidator trying to validate the volume after detecting some error in the disk data structures on bootup. What it does is it disables writing on the volume during the validation and sets the available space to 0.
Just wait and let it finish, which may take a long time (even hours, don't remember exactly). Then it will show the real free space and allow writing again - unless it fails to validate for some reason. In that case your only option will be to backup the data, reformat and copy back.
Best regards,
Niels
