In the determination of a likelihood of bias the test is not subjective but objective. In other words, it is from the point of view of a reasonable man who happened to be present in the court and watched the proceedings. In Chief Abiola v. Federal Republic of Nigeria (1995) 7 NWLR (pt.405) 1, the Supreme Court referred to its earlier decision in Deduwa v. Okorodudu (1976) 1 NMLR 236 in which the court cited with approval what Lord Denning said in Metropolitan properties Co. Ltd v. Lannan and Others: “In considering whether there was a real likelihood of bias, the court does not look at the mind of the justice himself or at the mind of the chairman of the tribunal, or whoever it may be, who sits in a judicial capacity. 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, and then he should not sit. And if he sits, his decision cannot stand … The court will not inquire whether he did, in fact, favour one side unfairly. Suffice it that reasonable people might think he did. The reason is plain enough. Justice must be rooted in confidence; and confidence is destroyed when right-minded people go away thinking: ‘The Judge was biased.” The moment right-minded or right-thinking people are of the view that the Judge was biased or there was likelihood of bias so much violence is done to the fair hearing principles as contained in section 33(1) of the 1979 constitution. This is because the Judge in his biased mind has closed the frontiers of fair hearing against the party he hates as he opens the door to accommodate the case of the party he favours. That is injustice and a court of Law should not be involved in it.
— Niki Tobi, JCA. Nnamdi Eriobuna & Ors. V. Ikechukwu Obiorah (CA/E/77/99, 24 May 1999)