The principle at risk here is Independence. According to ISO 19011:2018 – Clause 4(c), auditors must be independent of the activity being audited and free from bias or conflicts of interest.

Having previously consulted for the company on diversity strategies, the auditor has a prior engagement that may affect impartiality, particularly since the audit involves evaluating bias and fairness in hiring practices — the same area previously advised on.

The PECB Lead Auditor Guide – Domain 3 reinforces that independence is crucial for objective evidence gathering and unbiased conclusions, especially in audits involving ethical or reputational concerns.