Canada’s legal system, like many others, is adversarial. Each side brings forward evidence and a judge determines the truth, which often lies somewhere in the middle.
But the legal process itself can have an impact on which version of the “truth” the judge decides is correct: when a case drags on for months, judge and jury may forget earlier testimony, points out U of T law professor Simon Stern. This can happen especially with expert witnesses – those who provide the court with specialized knowledge and, unlike “fact” witnesses, are allowed to state opinions.
Australia gets around this problem by putting the expert witnesses in the same room at the same time and allowing experts from opposing sides to directly challenge each other – a practice playfully known as “hot tubbing.” Stern says the technique works well in technical cases where the two experts have similar levels of expertise and are both testifying on the same issue. Judges like it because it allows them to evaluate both sides’ claims quickly and effectively; lawyers don’t, as they are less able to script their witnesses.