In what circumstances will a juror be found to have made reference to the existence of a black judge?

In the case of Johns v. City of Los Angeles (1978) 78 Cal.App.3d 983, 991, 995-996, 144 Cal.Rptr. 629, a juror was alleged to have made reference as follows: " 'I wonder how long these lawyers shopped to get this black judge.' " (The defendants were black.) A new trial had been granted and was ordered reversed by this decision. The court stated: "To extrapolate from the alleged statement a finding that at the time the juror answered the voir dire question he did not do so honestly and without a bias which would prevent him from giving the plaintiffs a fair trial, requires considerable speculation.