Prosecution of experts in the wake of disasters has emerged as common in the context of increasing social intolerance of risk. This paper examines expert blame using as a case study the decisions of engineers who operated Wivenhoe Dam during the Queensland floods in January 2011 and the criticisms of those decisions by the subsequent Commission of Inquiry. Our analysis draws on the literature on organisational safety, organisational learning and expertise to examine the relevance of the criteria against which the engineers were judged, the relevant competence of those who made this assessment and the broader implications of such exercises. Our analysis shows that lay judgements of expert practice can be misleading, as evidenced by the Commission of Inquiry’s misguided focus on procedural adherence. We argue that such inquiries—where the focus is on assigning blame—detract from opportunities to learn from incidents and can negatively impact on professional practices. If the aim is to make future disasters less likely, then inquiries that take this approach may be failing in this endeavour, or at least not maximising their contribution.