Can a Witness Testify Without Personal Knowledge of a Subject ?
In Gibson v. Workers' Compensation Appeal Board (Armco Stainless), 580 Pa. 470, 861 A.2d 938 (2004), the Supreme Court discussed the value of lay testimony in great detail.
In that case, the Supreme Court concluded that the claimant's testimony, submitted to support the factual issue of exposure (existence of element in workplace), did not constitute substantial evidence in support of that factual issue because he did not have personal knowledge or firsthand experience with the disease-causing element, asbestos: "No witness with firsthand knowledge testified that there was asbestos in the workplace.
Mr. Grier simply testified that he saw Decedent near a dusty, cottony material that he was unable to identify." Gibson. 580 Pa. at 483-4, 861 A.2d at 946.
The Supreme Court concluded that "there simply is a lack of substantial evidence, either competent or sufficient, to support a finding that Decedent's death was caused, in substantial part, by asbestos-related disease." Gibson, 580 Pa. at 484, 861 A.2d at 946.
Significantly, the Court, while recognizing the long-standing principle that rules of evidence are relaxed in administrative proceedings, stated:
We believe that another fundamental rule of law is that witnesses must have first-hand knowledge of the subject on which they are testifying for that testimony to be admissible.
Stated succinctly, evidentiary Rules 602, 701, and 702 are applicable to agency proceedings in general, including workers' compensation proceedings. Id., 580 Pa. at 486, 861 A.2d at 947.