Each of the experts in this case gave their evidence over three or four days and no doubt the cross-examination was grueling. The court contrasted the approaches taken by the causation experts for both sides.
The experts for the plaintiff gave their evidence in an objective, forthright and comprehensive manner. They made concessions in cross-examination where it was warranted.9 They provided explanations that were thorough, comprehensive and made common sense.10 The court appreciated the evidence given by the plaintiff’s standard of care expert, but noted that his finding that the defendant breached the standard of care was based principally on admissions made during the cross-examination of the defence expert, as well as some of the defendant’s own testimony.
In commenting on the causation defence experts, the court noted that they did not mention a key feature on the imaging, the dissection in the left vertebral artery at the C5/C6 level (described by a plaintiff’s expert as the “smoking gun”) in their initial opinions, which raised doubt over the reliability of their opinions on causation.11 One defence expert readily admitted that he had overlooked the dissection at the C5/C6 level12 and when questioned further he was dismissive of the importance of it. One defence expert agreed that it would have been best if he had reported on that irregularity, but the court found that concession to be compromised by a sarcastic follow up comment.13
Preparing one’s experts for cross-examination is a critical step in the preparation for trial, including what questions to expect and when and how to make concessions if appropriate. Although the demeanour of an expert in the witness box is not a factor to be considered when a court weighs conflicting expert evidence,14 a reluctance to make concessions when warranted, and a retreat to sarcasm or dismissing the importance of key evidence has the potential to colour the courts’ weighing of that evidence.