Fix: orchestrator flow (#2699)

## Motivation and Context
<!--- Why is this change required? What problem does it solve? -->
<!--- If it fixes an open issue, please link to the issue here -->
Necessary before we can implement retries.

## Description
<!--- Describe your changes in detail -->
I noticed that we weren't handling the flow quite right when errors
occurred. This PR fixes that and adds interceptor-based tests to ensure
things are working right. I still think we could use more tests but the
PR is already quite large.

## Testing
<!--- Please describe in detail how you tested your changes -->
<!--- Include details of your testing environment, and the tests you ran
to -->
<!--- see how your change affects other areas of the code, etc. -->
This PR contains tests

----

_By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice._