The one thing I will say is that the capex was kept to a better figure than many predicted. The capex figure is more accurate and not as prone to tweaking variable information as the NPV or using ROV. Teck would also be able to run their own capex at a better rate, and verify the accuracy with quotes of their own.
Teck should be able to take the capex and understand that the rest of the information in the feasibility are flexible in the sense that improvements can be made. The capex already anticipated the increase to 180,000 tpd and the NTL costs. So it is a real solid number whereas the NPV or ROV seem a little more open to interpretation.
I don't know how this gets incorporated into the value exactly but since climbing capex costs seems to be a major concern getting this one in properly should be the major consideration. If Teck believes that the other information can be improved, like increasing the metal recoveries, upgrading those inferred to reserves, shortening the development time and that the potential for this being a district is real, then the most significant figure is the Capex. (Well, and the Opex, which was less good but still real.)