Examiner's car upset bull (7)
I believe the answer is:
auditor
'examiner's' is the definition.
(an auditor examines accounts etc)
'car upset bull' is the wordplay.
'car' becomes 'audi' (audi is a german car brand).
'upset' says the letters should be written in reverse.
'bull' becomes 'rot' (synonyms).
'rot' reversed gives 'tor'.
'audi'+'tor'='AUDITOR'
(Other definitions for auditor that I've seen before include "I hear" , "Business accountant" , "Accounts checker" , "Checker of books" , "Listener; checker" .)