The owner can appoint a Contract Administrator from their staff, but since the CA is in an inherent Conflict of Interest,, there may be a shortage of volunteers!
The CCA is an MMCD contract administration expert. Certified Contract Administrators (CCAs) voluntarily undertake a rigorous certification process through MMCD Association, which includes providing proof of education, practical experience, and professional references, a 16-hour training course, and writing a certification examination – all to ensure a fair process for all parties involved in completing your contract.
Situation may require legal advice...but check the GCs for sections relevant to the alleged breach.
Check out the “Contract Considerations” video “Quality Assurance and Quality Control Testing” on the MMCD website mmcd.net.
It depends whether there was an Act or omission by the Owner regarding knowledge of the Unknown concealed condition; and whether the CA responded within the time limits to any written request for Additional instructions.
The User Guide (10.3.2.1, 10.3.2.2) suggests that Owner caused delays (per GC13.1) entitle the Contractor to reimbursement for costs and lost time. In this case, the CA must act impartially and issue a Change Order for the proven impact, even if the CA was the cause of the delay.
The Contract Considerations Video, "Partial vs. Staged Substantial Performance" should provide the answer.
Refer to GC 1..3.8