What does Armstrong recall about the Seton case that judge wargrave adjudicated

Wargrave tells them he has a clear conscience over the man he is accused of murdering, a defendant in a trial who was convicted and sentenced to death by the judge. Dr. Armstrong remembers the case and recalls that he heard rumors that the judge in the case had been unfair. Armstrong asks the judge if he knew the convicted defendant before the trial. Wargrave denies it, but Armstrong thinks to himself that he knows the judge is lying