“There is a strong presumption of judicial impartiality and a heavy burden on a party who seeks to rebut this presumption. The long-standing test is this: what would an informed person, viewing the matter realistically and practically – and having thought the matter through – conclude: see Marchand (Litigation guardian of) v. Public General Hospital Society of Chatham (2000), 51 O.R. (3d) 97 (C.A.), at para. 131.
This two-fold objective test 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.
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 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.”