A free agent on broadcast probing drawback of celebrity (4,3,3)

'probing drawback of celebrity' is the definition.
I know nothing about this answer so I can't tell whether this works.

'a free agent on broadcast' is the wordplay.
I cannot really understand how this works, but
'a' could be 'one' and 'one' is located in the answer.
'broadcast' could be 'sown' (I've seen this before) and 'sown' is found within the answer.
The remaining letters 'man' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?