Expert Testimony Based On Mold Exposure Assumptions Excluded

David C. Swedelson, from the HOA Law Blog, has provided a summary of a mold case in California, with additional summary provided by David Stearn of West Coast Casualty Service, Inc.:

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...

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.

Ron Tov, AIA