Can an expert be cross-examined on an inconsistency between their viva voce and their written report?

Inconsistencies between the viva voce evidence of an expert witness and his or her written report are the proper subject of cross-examination. However, if the expert witness was not cross-examined on an inconsistency between his or her viva voce evidence and the contents of the report, it is not open to a trial judge to place any weight in assessing the expert’s credibility on this perceived inconsistency. This is not a mere technicality, but rather a matter of trial fairness. The expert witness is entitled to be openly confronted with what may appear to be contradictions so that he or she has the opportunity to explain or clarify the apparent inconsistencies: Moore v. Getahun, 2015 ONCA 55, at para. 86. Learned Articles and Treatises