Administrator of the estate of the late John Miugai Mwobi v John Kimani Njoroge

The judge had disqualified herself as a Commissioner of Assize on the ground that she was known to one of the parties. That ground did not dissipate on her appointment as Judge. Although the parties and advocates failed to raise the objection and arguably waived and acquiesced, disqualification is a matter of law. Justice must not only be done but be seen to be done, and the fair-minded observer would apprehend bias from a judge revisiting a matter she had once declined to hear.

The court analysed the doctrines from Halsbury's Laws and local authority, accepted that the parties by silence and participation had waived their right to object and had acquiesced. However, it held that disqualification of a judge is a matter of law and not fact, so estoppel, waiver and acquiescence do not apply to cure the defect.

The court reviewed Kenyan precedent including Uhuru Highway v Exchange Bank (which had adopted R v Gough) and Kimani v Njoroge, where the majority preferred Lord Denning's formulation in Metropolitan Properties v Lannon. The court expressed agreement with the impression-on-right-minded-persons test and anchored the requirement of impartiality in Article 50 of the Constitution and section 77(9) of the repealed Constitution.

The court noted that several advocates came on record over the years, evidenced by Notices of Change of Advocates, and a diligent advocate ought to have discovered the earlier disqualification and raised it. Although the failure did not validate the proceedings, the court criticised the advocates for allowing the judge to conduct the trial and reflected this in making no order as to costs.