Just came across a nasty little bug in the backend workflows. Have the parameters set on the backend workflow and it is mandatory (user parameter)
Despite the fact that the result of step 1 to find the user was successful and that the parameter is mandatory, which means, even if the step 1 find user was not successful in the logs should have seen the parameter value as empty. Instead the nasty little bug is such that the mandatory parameter was not even requested.
Be on the lookout for issues like this on backend workflows.