Here is a link to an article I wrote many years ago on precedence / hierarchy of documents under NEC : http://www.jonbroome.com/getattachment/44704d3b-547d-4bd9-a278-b40389ffcc58/Is-there-a-hierarchy-of-documents-under-the-ECC.aspx
Without knowing the details, the Z clauses stating the Contractor has responsibility for design development would have precedence over the risks stated in the Employer's Works Information.
However, in cases like this, my experience is that the devil is in the detail of the precise wording, both of the Z clauses and the WI, and of what happened in practice i.e . who did / didn't do what and when. E.g.if the Accepted Programme said that the Employer supplies information to base your design on and they did not do it, then that is probably (depending on the Z clause wording) a compensation event.
Without knowing the details, the Z clauses stating the Contractor has responsibility for design development would have precedence over the risks stated in the Employer's Works Information.
However, in cases like this, my experience is that the devil is in the detail of the precise wording, both of the Z clauses and the WI, and of what happened in practice i.e . who did / didn't do what and when. E.g.if the Accepted Programme said that the Employer supplies information to base your design on and they did not do it, then that is probably (depending on the Z clause wording) a compensation event.