Who Holds the Risk: The Criterion Engineer, the Design Build Contractor or the Design Build Engineer?

What is the contractor to quote if the criterion engineer requests an incomplete system that may not be correctly sized for the project? The contractor is at risk to deliver a complete system, with all operational components from abridging documents that are purposely incomplete. This contractor is responsible to hire the design build engineer of record, responsible for a complete functional system after he has quoted a fixed cost for the system. In this example, relationships clouded best practice.