When a company pays a big fee to fill a contingency placement, it is key to submit the right type of candidate. Thus, finding the must have requirements for a position is big. If a candidate is close but is missing one and especially two must haves. Then, it is best not to move forward with the candidate.
For example, if the client is asking for an Organizational Development person with direct experience in a manufacturing environment. I would not submit someone who has everything else but is missing the key experience in a manufacturing environment.
Give the client what he wants, not close to what he wants.