In practice when restoring data, only a few would ensure that the data has been really retrieved, however, such a verification is mentioned in most instructions about data recovery (e.g. in data recovery guide first actions).
So the following situation may happen:
- you recover files and folder tree seems reasonably correct,
- you format the hard disk, discard it, or make the disk useless in some other way,
- you see that the recovered data is corrupted.
It is needed to try to extract data once again, but unfortunately you have already lost the initial hard disk content.
To sum up the above – it is needed to verify the extracted data first and after checking start to write data on the hard disk which was used in the data recovery.