Journalist Poirot identified going back inside (6)
I believe the answer is:
editor
'journalist' is the definition.
(thesaurus)
'poirot identified going back inside' is the wordplay.
'inside' says the answer is hidden in the clue.
'going back' says the letters should be written in reverse.
'rotide' is hidden within 'poirot identified'.
'rotide' written backwards gives 'EDITOR'.
(Other definitions for editor that I've seen before include "one to give some publicity?" , "One is in charge of publication" , "One who orders copy" , "Director of publication" , "Do tire out the press person" .)