Doctor's opinion that chemical exposure caused loss of smell is admissible

When a Lowe's employee opened the packaging on some pool chemicals, one bottle was punctured, but still placed on a retail shelf.  David Best suffered a chemical burn on his face and hands when he pulled the bottle off the shelf to examine it.  Soon after, he lost his sense of smell completely.  His doctor confirmed that he suffered from "permanent anosmia" and by means of differential diagnosis the doctor excluded other possible causes of the loss.  Lowes persuaded the trial judge to dismiss Best's case, however, by persuading the judge that the doctor's expert opinion was unduly "speculative".

The Sixth Circuit Court of Appeals reversed the trial judge, however, in a unanimous opinion.  It concluded that the doctor had made a reasoned differential diagnosis by examining and excluding all of the other known potential causes of Best's loss.  It also pointed out that the doctor's testimony was supported by the warnings on the product and by the doctor's experience with other patients who suffered from anosmia, or who had suffered chemical exposures. It determined that he had made "a principled effort to eliminate the other possible causes" of Best's injury, and had provided a reasonable explanation of why he concluded that alternative causes suggested by the defense were not the sole cause.