Skip to content

Expert evidence

|Written By Julius Melnitzer

Hot tubbing, also known as concurrent evidence, has come to the Ontario Energy Board.

“The concept envisages competing expert witnesses testifying together and being jointly questioned by the judge or tribunal and counsel and, sometimes, by each other,” says Glenn Zacher of Stikeman Elliott LLP.

The practice originated in Australia in the 1970s and is now common in that country’s courts. Other jurisdictions have adopted it as well.

In Canada, the Federal Court was the first to incorporate it in 2010. The Competition Tribunal followed.

When Ontario amended its Rules of Civil Procedure with the aim of expediting proceedings and reducing costs, it included a provision allowing something akin to pretrial hot-tubbing type meetings between opposing experts intended to narrow the issues at trial.

But the introduction of hot tubbing at the energy board was a surprise for some.

“The board proposed it out of the blue in December 2011 in the Canadian Distributed Antenna Systems Coalition case and codified it by amending its rules of practice and procedure about a month later,” says Zacher.

The issue arose when the board invited written submissions on whether a conflict of interest or a reasonable apprehension of bias arose by having professor Roger Ware, an expert retained by the coalition who was also a member of the market surveillance panel, appear as an expert witness.

The coalition volunteered to withdraw Ware’s evidence. The board agreed but at that point imposed the hot-tubbing procedure on the experts for all parties.

The amendments that followed gave the board the power to require experts to confer with each other in advance of a hearing for the purposes of narrowing the issues, identifying points on which their views aligned or differed, and preparing joint written statements to be admissible as evidence at the hearing.

The board may also require experts to appear together at the hearing as a concurrent panel for the purposes of answering questions and commenting on each other’s views.

According to Zacher, the rule amendments are broad and will give panels “significant latitude in deciding whether and how to employ this practice. It will be of great interest to the sector to see how this unfolds, but the devil is in the details.”

Those details include tricky issues such as whether the experts’ caucus will be without prejudice.

“If you want frank discussion, you have to make the discussions privileged,” Zacher says.

Other issues involve whether counsel will be able to attend the caucus; the order in which experts testifying together will face cross-examination; and whether the tribunal will begin the questioning or not.

A controversial topic, hot tubbing has as many detractors as it does proponents.

“Many lawyers disparage hot tubbing, some of them because they’re comfortable with the processes they know and are wary of change,” says Zacher.

“But there are valid criticisms, many of which focus on the good reasons that exist for the time-honoured rules of evidence, the clear rules as to who goes first, the discrete roles of examination and cross-examination, and the sharp lines between what judges do and what counsel do.”

As Zacher sees it, however, this line of criticism is more relevant in the courtroom setting than it is at the energy board.

The board, he notes, “is an economic regulator deciding things in the public interest and typically goes about its job by balancing the economic interests of consumers or ratepayers on the one hand and utilities and investors on the other.

Unlike a courtroom, it’s not truth or what’s right or wrong that’s at stake, and so the historical controls are not as relevant.”

Detractors also argue that when experts testify together, expertise can become secondary to debating skills.

But proponents counter that hot tubbing discourages experts from being advocates and overstating their views.

As former Supreme Court of Canada justice Ian Binnie put it: “The theory is that experts testifying in the presence of one another are likely to be more measured and complete in their pronouncement, knowing that exaggeration or errors will be pounced upon instantly by a learned colleague, as opposed to being argued about days later, perhaps by unlearned opposing counsel.”

Proponents add that hot tubbing increases efficiencies by allowing judges and tribunals to make more sense of complex technical matters and focus on the real issues.

Still, caution abounds.

“In a general way, hot tubbing is probably a good thing, especially by way of narrowing the issues, but we’ll have to see how it works out,” says Zacher’s colleague Patrick Duffy.

cover image

DIGITAL EDITION

Subscribers get early and easy access to Law Times.

Law Times Poll


The Law Society of Upper Canada is requiring all licensed lawyers to write a statement of principles acknowledging their obligation to promote equality, diversity and inclusion. Do you agree with this requirement?
RESULTS ❯