Taleo - Not sure how User profile has been automatically updated by service account.

Summary:

We have noticed that a few of our user accounts have been automatically updated by a service account in Taleo.
The changes that were made was that it changed access roles from "Recruiter" to "Hiring Manager".
We have searched up the service account but cannot find any traces of any associated batch jobs which would have caused this change.
Would anyone know how to dig down into these changes and where this account can be found? or what jobs are able to update these?

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