A trial judge who rejects the evidence of a qualified expert witness must give detailed, sensible reasons for doing so; a bare assertion that the expert's conclusions are unacceptable or illogical is insufficient. Where goods share a common design defect and some are found to be of unmerchantable quality, a finding of unmerchantable quality cannot rationally be limited to only those goods that actually failed in use. A perception of bias arising from a trial judge's conduct will carry over to a new trial, requiring the new trial to be conducted by a different judge.
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