Ian
you are obviously referring to Delay as a caused by the Client. However the NEC does require the plan to show cl32.1 How the Contractor plans to deal with ANY delays, here we have an interpretation.
The Revised Program is a record of the events on site resulting from Both Client and Contractors, Progress, events, PMI's etc.
But there is an onus on the Contractor in his submission of the Revised Program how he intend to deal with any delays and how he is to rectify them.
However if the Contractor become aware of any matter that , as as soon as he become aware, that could affect the Contract cl16.1 a Risk Reduction Meeting must be held , the aim of this is clearly spelt out in Cl16.3
So my view would be that there would be a binding obligation , within the contract to, to reduce and mitigate delay even this caused by the Employer?
Regards