Mistaking one end of mastoid for the other, accept responsibility for flat bone (8,5)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
shoulder blade
'flat bone' is the definition.
I don't understand how the remainder of the clue works.
(Other definitions for shoulder blade that I've seen before include "joint?" , "Scapula" , "bone" .)
I've seen this clue in The Times.
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