On May 28, 2009, in the matter of Dee v. PCS Property Management Inc. the California Courts of Appeal – 2nd District ruled that proposed expert testimony is properly excluded where experts relied on unsupported assumption that mold exposure caused plaintiff’s symptoms.
In this mold case, the plaintiff Darcee Dee lived in an apartment complex. In 2001, tests showed that stachybotrys, a type of mold capable of producing mycotoxins (often referred to as the toxic mold), was present in Dee’s apartment. Dee sued the owner of the apartment building and others, claiming that the mold caused her to suffer numerous ailments and increased the risk of cancer.
At trial, Dee proposed to include testimony from her treating physicians that her numerous ailments were caused by exposure to mycotoxins. However, the trial court excluded her experts’ testimony under Evidence Code Section 801 on the grounds that there was no reasonable basis for their opinions. Although the experts’ testimony was limited, they testified that Dee’s symptoms were consistent with mold exposure. The jury found that the defendants were not negligent.
The Court of Appeals affirmed and found that Section 801 limits the expert witness testimony to matters personally known to that expert that may be reasonably relied upon by an expert of that field in forming an opinion. An expert witness’ opinion based on assumptions of fact has no evidentiary value and should be excluded from evidence. In this case, Dee’s treating physicians sought to testify that Dee’s exposure to mycotoxins caused her symptoms and made her susceptible to cancer. Although the stachybotrys in Dee’s apartment was capable of forming mycotoxins, there was no conclusive evidence as to Dee’s actual exposure to mycotoxins. The court found that the opinions of Dee’s treating physicians were based on assumptions of fact and the exclusion of their testimony was proper.
If you would like to read the actual opinion of the Court of Appeal, click here.
This summary was in part provided by David Stern RPA of West Coast Casualty Service, Inc.