In reply: Hindsight bias in medicolegal expert reports

In reply: We agree with Arnold that, ideally, expert witnesses should attempt to assess management decisions before acquainting themselves with the outcome and allegations in negligence cases. In practice, we suspect this is rarely done. In any case, the mere seeking of an expert opinion conveys the information that there has been an adverse outcome and, as we noted, there is evidence that, even if experts attempt to guard against it, hindsight bias is unavoidable in such circumstances. The central problem is that the expert is, as it were, looking back down one fork in the pathway of events, whereas the treating doctor was looking forwards at many possible and often uncertain forks.1