Details not finalised, so one's led into error (5,4)

I believe the answer is:

loose ends

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'one's led into error' is the definition.
I can't tell whether this defines the answer.

'details not finalised so' is the wordplay.
'details' becomes 'looseend' (I can't explain this - if you can you should believe this answer much more).
'not finalised' means to remove the last letter.
'so' with its last letter taken away is 's'.
'looseend'+'s'='LOOSE ENDS'

Can you help me to learn more?

(Other definitions for loose ends that I've seen before include "details yet to be explained" , "items to be settled" , "Unfinished business" .)

I've seen this clue in The Guardian.

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