Leaving as a result of being fired (5,3)

I believe the answer is:

going off

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'a result of being fired' is the definition.
I can't judge whether this definition defines the answer.

'leaving as' is the wordplay.
'leaving' becomes 'going' (synonyms).
'as' becomes 'off' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'going'+'off'='GOING OFF'

Can you help me to learn more?

I've seen this clue in The Globe and Mail, The Telegraph and The Guardian.

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