Tableau Server In-Place Upgrade Fails on Re-execution of Upgrade Script due to Server Running

When a Tableau Server in-place upgrade fails and Tableau Server is started to address that particular failure, then when the upgrade script is re-run to continue the upgrade process, the script's checkpoint logic skips the stop step because it already ran during the original attempt. 

The script logs:

StopServicesOperation is in checkpoint list. Skipping.
VerifyServerStoppedOperation is in checkpoint list but is configured to always run.

The checkpoint logic to determine where the script should continue the upgrade assumes the server was never restarted after the original failure and simply picks up where it left off — but it has no awareness that the Tableau Server was started in the interim.