I’ve spent two years arguing that AI detection tools are close to worthless. I still think the studies showing they flag non-native English speakers at higher rates are damning, and I still think any university disciplining a student on the strength of a probability score is committing an injustice it will eventually have to apologize for. None of that has changed. But there’s a category of case where the objection collapses, and we just watched a clean example of it.

GPTZero has identified apparent AI-generated hallucinations in four PwC Middle East reports, following earlier investigations by the same firm that led EY and KPMG to retract reports containing similar fabrications. Three of the four largest professional services firms have now had published client-facing work called into question by an outside detection vendor. The pattern matters more than any individual document. These are not internal drafts or marketing pieces. They are deliverables carrying a firm’s name, produced under engagement letters, and in some cases used as inputs to investment and policy decisions.