How is a file marked as being bad (corrupt files etc)?
You need to use the sam_admin command: sam_admin update file content status to mark the file as being bad. Such files will no longer be delivered to user projects. If the request does not include a reason for marking the file bad, ask the user for the reason, so that it gets documented in the issue tracker system. If the reason is a corrupted file, check that it has been downloaded correctly and that it isn’t corrupt on tape.