Could you explain this sentence ( this may force the auditor into changing their approach to any remaining procedures which would be considered to be undue influence of the client over the procedures performed )
If whatever “this” is (you do not specify) makes the auditor do something other than the planned audit procedures, the auditor’s objectivity has been compromised. A client cannot dictate audit procedures – any pressure from the client on the auditor may be described as undue influence.