Two ironworkers, Richie Dilts and Matthew Collins, were killed when a steel panel there were standing on fell about 80 feet. Their estates sued and offered expert testimony from an accident reconstructionists, Stuart Nightenhelser, regarding why and how the panel fell. But the district court excluded the expert's testimony, a ruling the Sixth Circuit reversed in Dilts v. United Group Services, Nos. 10-5271, 10-5540 (September 17, 2012).
First, the court ruled that Nightenhelser possessed the necessary qualifications noting that he had a Bachelor of Science in physics and mathematics from Butler University, had worked in accident reconstruction for over a decade, regularly applied, as part of his job duties, laws of physics and mathematics to support his analysis and conclusions for the reconstruction of accidents and estimated that he had worked in over 1000 cases involving construction equipment, vehicles and the construction of buildings and other structures. That Nightenhelser may not have been familiar with all aspects of individual accidents was no grounds to exclude his testimony because "such lack of familiarity affects the witness's credibility, not his qualifications to testify." Davis v. Combustion Engineering, Inc., 742 F.2d 916, 919 (6th Cir. 1984).
Second, Nightenehlser's opinion was sufficiently reliable because he conducted an on-site inspection, photogrammetric analysis, performed calculations and algebraic equations along with other analytical steps. That Nightenhelser was not perfect and did not know everything did not disqualify him: "An expert's lack of experience in a particular subject matter does not render him unqualified so long as his general knowledge in the field can assist the trier of fact." See Sarkas ex rel Johnson v. Greyhound Lines, Inc., 474 F.3d 288, 293-94 (6th Cir. 2007). Accordingly, the Sixth Circuit ruled that the district court had erroneously excluded Nightenhelser's expert opinion and testimony.
The opinion for the Sixth Circuit was written by Circuit Judge Eric Clay and joined by Circuit Judges Julia Gibbons and Helene White.