If you're going to provide the path to the dump archive to ufsrestore you need to tell it with the 'f' switch (which says the next field on the command line is where the dump file is).
The sysadmin might well have created a script which read the vtoc and wrote it out to a file (.vtoc) and then snapshot the filesystem (fssnap), and then dumped it (ufsdump). So although ufsdump does...