Recent investigations into the Macarthur Health Service have resulted in multiple reviews of a small number of cases. This article was prompted by a casual observation that these reviews have resulted in differing conclusions about what occurred in each case and what might have been done in response. The reliability of peer review is examined, together with the literature on the scale of adverse events and the issue of problem identification. Potential sources of bias and error during peer review are considered. Drawing on the lessons from the literature and the experience of Macarthur, suggestions are made to improve the identification and review of adverse events.