What version are you running?
2.5.6.1
What's the URL of the page containing the problem?
N/A
What steps will reproduce the problem?

Create a user 'blah'
Give blah permission "reviews | review request | Can submit as another user"
rbtools post --submit-as USERNAME....
View review request in Review Board


What is the expected output? What do you see instead?
A completely empty review is created with no diff. And RBTools errors out when trying to do those steps.  
We expect to be able to fully create a review with only the "Can submit as another user" permission.
What operating system are you using? What browser?
RHEL 6.6 and Mac OS
Please provide any additional information below.
We have an automated account that should be able to create fully populated including attachments reviews as another user and publish that review, but once it is posted (either draft or published) that automated user should no longer be able to modify that review.