Evidence - Polygraph. Petti v. George Coppel Jewellers Ltd.
In Petti v. George Coppel Jewellers Ltd. (Dic Ct, 2008) the Divisional Court set out the rule that polygraph evidence in civil cases is not allowed to weigh towards truth as it amounts to a delegation by the judge of their credibility-assessing function:
 In legal proceedings, polygraph tests may be approached from three perspectives: (1) whether the taking of the polygraph test was volunteered or, if offered, rejected; (2) the questions asked and the answers given on the test; and, (3) the results of the test.
 With respect to (1) above, there seems to be some authority making narrowly relevant, in both criminal and civil cases, the fact that a litigant volunteered to take a polygraph test. For example, in R. v. B. (S.C.) (1997), 36 O.R. (3d) 516 (C.A.), a criminal case, at para. 29, the Court stated:
 Evidence that an accused offered to take a polygraph test has probative value only to the extent that it reasonably yields the inference that the accused was prepared to do something which a guilty person would not be prepared to do. In fact, an accused who offers to take a polygraph test risks nothing since the results are inadmissible: R. v. Beland and Phillips, [(1987), 1987 CanLII 27 (SCC), 36 C.C.C. (3d) 481 at 494-95 (S.C.C.)]. An inference favourable to the accused from such an offer could only be drawn if, despite the inadmissibility of the results, the accused believed that a negative test result could be used against him at trial . . .At para. 30, the Court added:
 Even if there was evidence that an accused believed that a polygraph test result could be used against him, the admissibility of a mere offer to take the test is still problematic. An offer to take the test is hardly an unequivocal act. Its probative value depends on a number of factors. What did the accused know about the accuracy of the test? Did the accused believe he could “fool” the machine? What advice did the accused have before making the offer? Was the offer a bona fide one? These and other possible considerations could lead to extensive inquiries into matters which are far removed from the question of the accused’s culpability in the offence charged. Evidence proffered by the defence will be excluded where its probative value is substantially outweighed by its prejudicial effect on the proceedings . . . In Whiten v. Pilot Insurance Co. (1999), 1999 CanLII 3051 (ON CA), 42 O.R. (3d) 641 (C.A.), a civil case involving a claim for fire loss where the insurer alleged arson and refused to pay, at para. 34, the Court appears to have approved of viewing an offer to take a polygraph test as evidence of the “Whitens’ good faith” and “willingness to co-operate in resolving their claim.” The Court stated, “The offer to take a polygraph test was but one part of the total evidence showing the Whitens’ co-operation with Pilot’s investigation.” The Court went on to say, “The admissibility of the offer and the trial judge’s instructions on how the jury could use the offer are consistent with this court’s judgment in R. v. B. (S.C.).” Whiten was reversed by the Supreme Court of Canada at 2002 SCC 18 (CanLII),  1 S.C.R. 595 on the issue of punitive damages but, as to the polygraph, the Court stated, uncritically, at para. 24:
. . . the Whitens, in an attempt to satisfy Pilot that they did not set the fire, offered to take a polygraph test administered by an expert selected by Pilot. This was apparently accepted by the jury as a good faith offer made to allay Pilot’s suspicions. Pilot refused, without giving any reasons. Here, as both parties offered to take, and took, a polygraph test, this could not be relevant in ascertaining good faith (and, in any event, the trial judge did not use the tests for that purpose).
 In a proper case, the questions and answers on a polygraph test – (2) above – may be admissible where, for example, the answers constitute an admission against interest. That is not the situation at bar.
 The results of a polygraph test – (3) above – are not admissible in an Ontario court, as those results usurp the very function of the trier of fact. And, if the results are tendered by a litigant who passed the test, they are tantamount to oath helping.
 In the case before me, the trial judge relied on the results of the polygraph tests, at least in part, when reaching his decision to dismiss the claim. In other words, the results were used to help decide the truth of the facts in dispute. In my view, this amounts to a reversible error. The error is not erased by the fact that the parties consented to the tests. The court should not delegate its jurisdiction, even on consent.