Price v. Blood Bank of Delaware, Inc.,
No. 191,2001 (Del. Feb. 14, 2002)

The estate of a deceased patient who had received a contaminated blood transfusion in 1984 and later died from AIDS contracted from that transfusion sued the blood bank for negligence in not properly screening blood donors. During the trial, both the estate and the blood bank presented expert witnesses on the issue of whether the blood bank had adopted adequate procedures for screening blood donors relative to the scientific knowledge of transmitting HIV through blood available in 1984. The jury ruled in favor of the blood bank. The estate appealed, claiming that the trial judge committed reversible error by displaying "obvious hostility" toward the estate's expert witness, irreparably damaging his credibility with the jury.

The Delaware Supreme Court agreed, reversed the trial court's verdict and granted the estate a new trial. The court held that the role of the trial judge as "gatekeeper" carried with it a "heightened requirement of impartiality whenever the trial judge engages in direct questioning of an expert witness" and that, in this case, the judge's questioning had been "aggressive and pointed." The court held that permitting the jury to consider and weigh the expert's testimony was an abuse of discretion because the judge had "tipped the scale of credibility against the [estate] in a critical factual determination."