Crossword Genius

Grew ponytail to supply admission of error (7,7)

Ross

I believe the answer is:

written apology

'admission of error' is the definition.

'grew ponytail to supply' is the wordplay.
'supply' indicates an anagram (in a supple way).
'grew'+'ponytail'+'to'='grewponytailto'
'grewponytailto' with letters rearranged gives 'WRITTEN APOLOGY'.

I've seen this clue in The Everyman puzzle in The Observer.
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