The disciplinary response when expert evidence departs from widely accepted professional practice. On occasion, a departure from widely accepted professional practice may manifest itself not as the provision of treatment, but rather in the giving of expert opinion evidence in reports,in pre-hearing conclaves or as oral evidence during a court hearing. This presentation surveys a few English and Australian examples and the regulatory/ judicial responses to such ‘innovative’ opinions. 2017 Australian Centre for Health Law Research (ACHLR) - Economic and Social Research Council (ESRC) Seminar Series, Liability and Innovation. The Effect of Disciplinary Proceedings.