Correct people nailed by journalist (5)
I believe the answer is:
emend
'correct' is the definition.
(to emend something is to correct or improve it)
'people nailed by journalist' is the wordplay.
'people' becomes 'men' (men are people).
'nailed by' is an insertion indicator.
'journalist' becomes 'ed' (short for editor).
'men' placed into 'ed' is 'EMEND'.
(Other definitions for emend that I've seen before include "Remove errors" , "make an improvement" , "Polish" , "Correct, revise (text)" , "Remove faults from" .)