At a legal seminar last week, Applegarth, who also heads the Queensland Law Reform Commission, urged barristers to apply more scrutiny to expert witnesses whose testimony influenced the outcome of cases and sentences.
“It is easy, sitting in the stands, to be critical of someone else’s performance on the field of play,” said Applegarth, a Supreme Court judge since 2008.
“But I am often perplexed by how easily expert witnesses in all manner of cases get away with expressing opinions without any serious challenge to their scientific or factual validity. In your run-of-the mill personal injury case, expert witnesses freely express predictions about whether someone’s physical or psychological injury will get better, worse or stay the same in the years and decades to come.
“These opinions are important. They can have a big effect on damages. Very few barristers bother to ask the witness about the empirical basis for their prediction.”
Applegarth said expert witnesses also made predictions about the likelihood of convicted sex offenders to re-offend, but he had not heard them asked whether past predictions had turned out to be correct.
Expert witnesses might stand on their experience, and confidence in their opinions, but Applegarth said was not enough. Even forensic pathologists had raised, outside court, the lack of scrutiny from barristers, while former judge Bill Pincus took it upon himself to ask questions, even if he ended with the rhetorical question “call yourself a scientist?”
“Compared to expert medical witnesses making predictions in court, weather forecasters don’t get it so easy,” Applegarth said.
“They have a rapid feedback loop and a very public demonstration when their opinions are wrong. As a result, they can improve the accuracy of their predictions.”
Applegarth said judges also needed to be aware of confirmation bias and cognitive bias, and their own role in directing juries in relation to expert testimony.Jump to next article