Review this article about independability of third party inspection agencies.The independence is one of the important conditions for inspection agency to be a Third Party Inspection Company.
You may need to review the third party independent inspection article in conjunction with the following articles:
The title of ISO 17020 is the general criteria for the operation of various types of bodies performing inspection.
Based the requirement of this standard, in clause 4.2:
“The inspection body shall be independent to the extent that is required with regard to the conditions under which it performs its services.”
The independence criteria for Third Party Inspection Companies detailed in Annex A of ISO 17020 is as below:
The procedures under which the body operates shall be administered in a nondiscriminatory manner.
So based on the above requirements, when either the buyer or seller make a contract with a third party inspection company, the judgment must be done independently.
In the case of a dispute between a buyer and seller, both parties should not expect the third party inspection judge to work in their interest.
Some buyers and sellers make the argument that they are the client, and a Third Party Inspection Company is the contractor, so the contractor must fully obey them.
But based on the third party independent inspection concept, this judgment is not correct and will damage the independence and integrity of the Third Party Inspection Company. If this happens, then nobody can trust to the third party inspection company's inspection and judgment.