Nothing in paragraph 9 shall impose any liability on the nominated undertaker with respect to any damage to the extent that it is attributable to the act, neglect or default of F2Canal & River Trust, its officers, servants, contractors or agents but the fact that any work or thing has been executed or done in accordance with a plan approved or deemed to be approved by F2Canal & River Trust, or to its satisfaction, or in accordance with a determination under paragraph 11, shall not (in the absence of negligence on the part of F2Canal & River Trust, its officers, servants, contractors or agents) relieve the nominated undertaker from any liability under the provisions of this Part.