After there Restore there is no special bitwise verification afterwards. The completion message just means, that the Windows i/o rouines completed all write operations without error. To make a verification, the newly written image would have to be read again and compared against the master image. USB Image Tool doesn't do this currently.
However, you can perform a verify yourself, by making a backup of the newly written flash drive. You can either let USB Image Tool create a MD5 hash and compare it with the one, you might have from the original image or make a file compare with an external tool.
