Ghorse

Ghorse identified two manufacturing units, Cee and Gee, which it had decided to dispose of in a single transaction. These units comprised non-current assets only. One of the units, Cee, had been impaired prior to the financial year-end on 30 September 2007 and it had been written down to its recoverable amount of $35 million.
The criteria in IFRS5, ‘Non-current Assets Held for Sale and Discontinued Operations’, for classification as held for sale, had been met for Cee and Gee at 30 September 2007. The following information related to the assets of the cash-generating units at 30 September 2007:
Depreciated Fair value less Carrying value
historical cost costs to sell under IFRS
and recoverable amt $m $m $m
Cee 50 35 35
Gee 70 90 70
–––– –––– ––––
120 125 105
–––– –––– ––––
The fair value less costs to sell had risen at the year-end to $40 million for Cee and $95 million for Gee. The increase in the fair value less costs to sell had not been taken into account by Ghorse.

My question is that :
when checking for impairment, The impairment comes to $15 for Cee.
But because at the year-end the recoverable amount of Cee went up to $40 and so now there should be a $10 impairment but instead, the impairment of $15 is being added instead of being deducted from the assets. Why is that? I am really confused.