How did you try to open the file with Finder?
What I would do would be to:
- close all databases in DT
- rename the restored database “Organization_Restore.dtSparse”
- open the restored database with DT
- restore the individual file by copying it from DT to desktop
- close the restored database in DT
- open the current version of the database in DT
- copy the file from desktop to DT
Take a moment to read this post.
If the problem you are reporting is a real permissions issue, then please post here the the information provided at the bottom of the info window in Finder (select Get Info from the context menu of the sparseimage file in Finder).