Another buggy workflow:
1. Brent submits diff -> diff status is "Needs Review"
2. Evan approves diff -> diff status changes to "Approved"
3. Brent removes Evan as reviewer -> diff status is still "Approved".
Seems like step 3 should change the status back to "Needs Review", as a diff should only be considered accepted if one of the reviewers' status is accepted, and Evan is no longer a reviewer.