Backup Server in itself does not perform any login credentials check. As long as the BS is started by the same UNIX login as the dataserver, you are fine.
You will find that you can log into backup server like you do on the dataserver using pretty much any login that you want. However, there is nothing you can do at the prompt(well, very limited which are not documented), not even a shutdown.
So to the right check for you to gurantee that dump will work is to make sure that the owner of the pid for dataserver and BS is the same. This can be done using fuser