Assessment of sums payable
70. In the assessment of any sums payable to the operator under this Part of this Schedule there must not be taken into account any increase in the sums claimed that is attributable to any action taken by or any agreement entered into by the operator if that action or agreement was not reasonably necessary and was taken or entered into with a view to obtaining the payment of those sums by Network Rail under this Part of this Schedule or increasing the sums so payable.