[The physician as an expert in medical negligence cases]

Whenever a physician is charged with negligence, the professional opinion of another doctor is always required. The quality of the expert report is a decisive factor in the quality of the ruling by the adjudicator. Three main problems may arise here: the medical expert may push up the professional standard, experts may differ in opinion, and finally their judgment may be influenced by prior knowledge of the outcome (hindsight bias). To avoid these problems, a systematic approach is needed, taking into account the scientific context, the clinical context, the procedure followed, the degree to which the outcome corresponds with the predicted outcome, reappraisal of the facts and the organisational context. In particular, the problem of hindsight bias through prior knowledge of the (unhappy) outcome highlights the need for greater attention to scientific and procedural aspects in the formation of an expert opinion.