Bias in Adjudicators - Presumption of Impartiality. Isaac v. Law Society of Ontario
In Isaac v. Law Society of Ontario (Div Court, 2022) the Divisional Court considered the law of bias:
 Judges are presumed to act impartially. The burden is on Mr. Isaac to provide compelling evidence that Justice Corbett conducted himself in a way that gives rise to a real or perceived apprehension of bias: Khan v. 1806700 Ontario Inc, 2021 ONSC 1679 (Div. Ct.), at para. 38.. Stuart Budd & Sons Limited v. IFS Vehicle Distributors ULC
 A reasonable apprehension of bias exists when a reasonable, informed person would reasonably conclude it is more likely than not that the decision-maker consciously or unconsciously would not decide the matter fairly: Baker v. Canada (Minister of Citizenship and Immigration), 1999 CanLII 699 (SCC),  2 S.C.R. 817, at para. 46, Summit Energy Management Inc. v. Ontario Energy Board, 2012 ONSC 2753, at para. 53.
In Stuart Budd & Sons Limited v. IFS Vehicle Distributors ULC (Ont CA, 2016) an appeal was granted on a rare finding of bias against the motion judge below. The court cited the following principles as applicable to the issue, particularly that of impartiality:
Reasonable Apprehension of Bias. Langstaff v. Marson
 As noted by Abella J. in Yukon Francophone, at para. 21, the Supreme Court has consistently endorsed the test for a reasonable apprehension of bias as set out in de Grandpré J.’s dissenting opinion in Committee for Justice and Liberty v. National Energy Board, 1976 CanLII 2 (SCC),  1 S.C.R. 369, at p. 394:
“[W]hat would an informed person, viewing the matter realistically and practically — and having thought the matter through — conclude. Would he think that it is more likely than not that [the decision-maker], whether consciously or unconsciously, would not decide fairly.” The strong presumption of judicial impartiality is not easily displaced: Cojocaru v. British Columbia Women’s Hospital and Health Centre, 2013 SCC 30 (CanLII),  2 S.C.R. 357, at para. 22. A reasonable apprehension of bias requires a “real likelihood or probability of bias”: Arsenault-Cameron v. Prince Edward Island, 1999 CanLII 641 (SCC),  3 S.C.R. 851, at para. 2; R. v. S. (R.D.), 1997 CanLII 324 (SCC),  3 S.C.R. 484, per Cory J., at paras. 112-14. The test is an objective one, viewed from the perspective of an informed and reasonable observer: Chippewas of Mnjinkaning First Nation v. Chiefs of Ontario, 2010 ONCA 47 (CanLII), 265 O.A.C. 247, at para. 230, leave to appeal refused, 33613 (July 18, 2010). It is a high burden.
 Significantly, in assessing whether a judge’s presumption of impartiality has been displaced, his or her individual comments or conduct during the hearing of a matter should not be considered in isolation but within the context of the entire proceedings: S. (R.D.), per Cory J., at para. 134; Wewaykum Indian Band v. Canada, 2003 SCC 45 (CanLII),  2 S.C.R. 259, at para. 77.
 The objective of the test is to ensure both the reality and the appearance of a fair adjudicative process. Both are essential to maintaining public confidence in our system of justice: Yukon Francophone, at paras. 22-23. It is not normally possible to prove actual bias. If the impugned conduct or comments have the cumulative effect of raising a reasonable apprehension of bias, there is no need to consider the impact of the bias.
In Langstaff v. Marson (Ont CA, 2014) the court stated as follows regarding the doctrine of judicial bias:
 There is a strong presumption of judicial impartiality and a heavy burden on a party who seeks to rebut this presumption.. Stuart Budd & Sons Limited v. IFS Vehicle Distributors ULC
 Judicial impartiality has been called “the key to our judicial process”: see Wewaykum Indian Band v. Canada, 2003 SCC 45 (CanLII),  2 S.C.R. 259, at p. 288. Chief Justice Lamer referred to “public confidence in the impartiality of the judiciary” as “essential to the effectiveness of the court system”: see R. v. Campbell, 1997 CanLII 317 (SCC),  3 S.C.R. 3, at para 10. The presumption of impartiality anchors public confidence in the integrity of the administration of justice.
 An allegation of bias engages the very foundation of our judicial system. It calls into question not simply the personal integrity of the judge, but the integrity of the entire administration of justice.
 In order to rebut the presumption of impartiality, a test has been developed by the Supreme Court of Canada. It was first articulated by de Grandpré J. in his dissenting reasons in Committee for Justice and Liberty v. National Energy Board, 1976 CanLII 2 (SCC),  1 S.C.R. 369, at p. 394:
[T]he apprehension of bias must be a reasonable one held by reasonable and right minded persons, applying themselves to the question and obtaining thereon the required information. … [T]hat test is "what would an informed person, viewing the matter realistically and practically – and having thought the matter through – conclude. Would he think that it is more likely than not that [the judge], whether consciously or unconsciously, would not decide fairly." The Supreme Court has repeatedly endorsed this test. In his reasons in R. v. S. (R. D.), 1997 CanLII 324 (SCC),  3 S.C.R. 484, Cory J. explained, at para. 111, that the test set down by de Grandpré J. contains a “two-fold objective element”: not only must the person considering the alleged bias be reasonable, but “the apprehension of bias itself must also be reasonable in the circumstances of the case.” Cory J. added, at para. 113, that:
[T]he threshold for a finding of real or perceived bias is high. It is a finding that must be carefully considered since it calls into question an element of judicial integrity. Indeed an allegation of reasonable apprehension of bias calls into question not simply the personal integrity of the judge, but the integrity of the entire administration of justice. This two-fold objective element is based on reasonableness: the person considering the alleged bias must be reasonable and the apprehension of bias itself must also be reasonable. The reasonable person must be informed and know the relevant circumstances, including the traditions of integrity and impartiality on which the judicial system is based. A mere suspicion is not enough.
 The determination is also fact-specific. In Wewaykum, the Supreme Court held, at para. 77:
[T]his is an inquiry that remains highly fact-specific. In Man O’War Station Ltd. v. Auckland City Council (Judgment No. 1),  3 N.Z.L.R. 577,  UKPC 28, at par. 11, Lord Steyn stated that “This is a corner of the law in which the context, and the particular circumstances, are of supreme importance.” As a result, it cannot be addressed through peremptory rules…there are no “textbook” instances. Whether the facts, as established, point to financial or personal interest of the decision-maker; present or past link with a party, counsel or judge; earlier participation or knowledge of the litigation; or expression of views and activities, they must be addressed carefully in light of the entire context. There are no shortcuts. This stringent test for a party alleging apprehension of bias is grounded in the need to preserve the integrity of the judicial system. It also recognizes the need to maintain the public confidence in the judicial system. The analysis contemplates a hypothetical observer who is informed of all the facts. It does not depend upon the views or conclusions of the litigant.
 It has also been held that, in order to maintain public confidence in the administration of justice, the appearance of judicial impartiality is as important as the reality. In Metropolitan Properties Co. (F.G.C.) Ltd. v. Lannon,  3 All E.R. 304 (C.A.), at p. 310, Lord Denning M.R. stressed the importance of the appearance of judicial impartiality. He said:
[I]n considering whether there was a real likelihood of bias, the court does not look at the mind of the justice himself.... It does not look to see if there was a real likelihood that he would, or did, in fact favour one side at the expense of the other. The court looks at the impression which would be given to other people. Even if he was as impartial as could be, nevertheless, if right-minded persons would think that, in the circumstances, there was a real likelihood of bias on his part, then he should not sit. And if he does sit, his decision cannot stand. This passage was cited with approval by Major J. in his dissenting reasons in S.(R. D.), at para. 11, and by this court in Benedict v. Ontario 2000 CanLII 16884 (ON CA), (2000), 51 O.R. (3d) 147 (C.A.). In Benedict, the court added, at para. 20:
We note that while Lord Denning M.R. spoke in terms of a “real likelihood” rather than a “reasonable apprehension”, in National Energy Board de Grandpré J. took care to state that such variations in the expression used should not generally be treated as involving any substantive difference in the approach to be taken. “Reasonable apprehension”, “real likelihood”, “reasonable likelihood” and “reasonable suspicion” amount to the same standard.This reasoning accords with the decision of Lord Nolan in R. v. Bow Street Metropolitan Stipendiary Magistrate et al.,  1 All E.R. 577 (H.L.), at p. 592:
[I]n any case where the impartiality of the judge is in question, the appearance of the matter is just as important as the reality.The appearance of impartiality was emphasized in Weywakum, at para. 66:
[W]here disqualification is argued, the relevant inquiry is not whether there was in fact either conscious or unconscious bias on the part of the judge, but whether a reasonable person properly informed would apprehend that there was.
In Stuart Budd & Sons Limited v. IFS Vehicle Distributors ULC (Ont CA, 2016) the court considers the issue of 'integrity', closely-related to bias:
Presumption of Integrity
 Judges benefit from a presumption of integrity, which acknowledges that they are bound by their judicial oaths and will carry out their duties in accordance with their legal responsibilities: R. v. Teskey, 2007 SCC 25 (CanLII),  2 S.C.R. 267, at para. 29. In R. v. Arnaout, 2015 ONCA 655 (CanLII), at para. 18, this court described these responsibilities: “A judge must both weigh the case impartially in his or her own mind and ensure that the circumstances objectively demonstrate his or her impartiality to an informed and reasonable observer.”
 Although judges enjoy the benefit of the presumption of integrity, the presumption can be rebutted by a judge’s comments or conduct: Yukon Francophone School Board, Education Area #23 v. Yukon (Attorney General), 2015 SCC 25 (CanLII),  2 S.C.R. 282, at para. 27.