Is there a way to validate a bootable USB stick made using the SBAV tool?

I am looking to verify that the virus definitions and bootable OS contained on the resulting USB stick match what is expected. Does any kind of checksum or hash value come down with the virus definitions to validate against? Alternatively, is there a listing somewhere on the Sophos site that can confirm the files that were supposed to be part of any given virus definitions update?

I have been following the instructions for bootable drive creation from this article KB-000033912.