If the reason for the rejection is based on a real scientific basis .and the error was simple and can be treated and did not affect the performance of structure in any way my opinion is that the contractor pay all costs for the difference and if the error is essential and can be repaired, I do the same procedure ... If it can not be repaired, the contractor should remove construction with paying all the costs and even those resulting from the delay of work.
If the reason for the rejection is based on a real scientific basis .and the error was simple and can be treated and did not affect the performance of structure in any way my opinion is that the contractor pay all costs for the difference and if the error is essential and can be repaired, I do the same procedure ... If it can not be repaired, the contractor should remove construction with paying all the costs and even those resulting from the delay of work.
Reason for rejection if it is due to the violation of the contract between client and the contractor,then the contractor should redo the work as per the contract specifications.Consultant is the final authority who acts on behalf of the client.