This is a strict products liability and negligence case against Adams, the manufacturer of a plastic Adirondack chair that failed and rendered Ronald Scanlan a quadriplegic.
The Defendant filed motions to exclude opinions of three of the Plaintiff’s expert witnesses: Russell Dunn, Clifford Tribus and Joellen Gill. The Plaintiff filed a motion to exclude opinions of the Defendant‘s expert witness, Dr. David Jones.
Economics Expert Witness
David DeHaven Jones has over 40 years of experience in Economics and Forensic Economics. He earned his BA from the College of Wooster in 1966, and his MA and Ph.D. from Indiana University in 1968 and 1975, respectively.
Among other roles, Jones served as a Professor of Economics at the
University of St. Thomas and as the Director of Policy Analysis at the Minnesota Department of Economic Development. He has authored numerous publications, including “A Note on Life Expectancy and Mortality Adjustment,” Journal of Legal Economics.
Chemical Engineering Expert Witness
Russell Franklin Dunn is a Ph.D. chemical engineer, who has spent his career working in plastics manufacturing and teaching plastics engineering and safety at Vanderbilt University.
Spine Surgery Expert Witness
Clifford Boehe Tribus is a fellowship-trained, board-certified spine surgeon. He is a graduate of Johns Hopkins Medical School. His fellowship training was in spine surgery. He has been a professor of neurosurgery and orthopedics at the University of Wisconsin Medical School for over 30 years.
Human Factors Expert Witness
Joellen Gill attended Georgia Tech and Wright State Universities for her undergraduate work, earning a BS in human factors engineering in 1979. Her nearly four-decade career includes 15 years in aerospace and national defense industries as a human factors engineer specializing in safety and risk management.
Gill started part time at ACS in 1994 after completing a master’s degree in engineering, accepted a full-time position in 2005, then, after obtaining certification as a Human Factors Professional, was lead engineer on her first case just a year later. She is also a licensed tribometrist and a Certified Safety Professional.
Discussion by the Court
David Jones
The Plaintiff sought to exclude Jones’ testimony regarding the “mortality adjustment” and “worklife adjustment” applied to reduce the Plaintiff’s future damages.
Jones’s worklife adjustment to the Plaintiff’s future earning capacity is improper under Wisconsin law. To calculate the Plaintiff’s lost future earning capacity, the finder of fact must determine how many years the Plaintiff is expected to work and then assess the Plaintiff’s earning capacity for those years. For example, it would not make sense for the jury to determine that the Plaintiff could have worked until age 65, but then to reduce his earning capacity based on the likelihood that he would not be working at age 65. Jones’ “potential earnings loss” table reduced the Plaintiff’s potential earnings in each year based on a probability that the Plaintiff would not be working.
That necessarily underestimated the Plaintiff’s future earnings in the years that the jury decided the Plaintiff likely would be working. The Court granted the Plaintiff’s motion to exclude evidence of Jones’ worklife expectancy opinions as irrelevant and confusing to the jury.
The Court also excluded Jones’ “mortality adjustment” opinions for similar reasons. To support an award of future health care expenses under Wisconsin law, (1) there must be expert testimony of permanent injuries, requiring future medical treatment and the incurring of future medical expenses; and (2) an expert must establish the cost of such medical expenses.
Russell Dunn
The Defendant contended that Dunn’s opinions are not reliable because he relied solely on testing that ATS performed on the chair. This argument has no merit; an expert is entitled to base his opinion on reports or data generated by another.
The Defendant next argued that Dunn’s opinions related to risk management lacked sufficient scientific and factual foundation because he relied on two documents when forming these opinions and excluded consideration of the Defendant’s quality assurance standard operating procedures.
At trial, the Defendant will have the opportunity to cross-examine Dunn regarding the documents he did or did not consider when forming these opinions.
Next, the Defendant argued that Dunn’s alternative design proposals are not supported by sufficient facts or data or are not the product of reliable principles and methods. However, the Court found that Dunn’s report was sufficient to place the Defendant on notice that the Plaintiff may argue that the addition of antioxidants to the chair’s polymer is a safer alternative design.
The Defendant argued that Dunn’s opinions on the root cause of the chair’s failure are not reliable because he failed to consider the Plaintiff’s intoxication at the time of the accident. The fact that an alternative explanation or contributing cause existed did not make Dunn’s opinion unreliable.
The Defendant argued that Dunn’s opinions related to the Defendant not meeting the outdoor furniture industry’s standard of care were not supported by sufficient facts or data. Dunn was entitled to rely on the representative’s sworn testimony to conclude that the Defendant did not test for oxidative degradation. Therefore, the Court cannot conclude Dunn was wrong in relying on the information the Defendant produced in discovery.
Clifford Tribus
The Defendant argued that the Court should exclude the Plaintiff’s expert Clifford Tribus because he was not timely disclosed as a principal expert and was improperly designated as a rebuttal expert.
Tribus’ report rebuts the Defendant’s biomechanical expert’s conclusion that the severity of the injury indicates the Plaintiff must have been in motion when the injury occurred. Tribus was properly designated as a rebuttal expert.
The Defendant also argued that Tribus’ opinions are not based on sufficient facts or data and are unreliable. Tribus testified that he relied on the Plaintiff’s CT scan and MRI imaging to determine that a low velocity fall could have caused the Plaintiff’s injuries; he did not review any scholarly publications or perform additional research. This is despite the fact Tribus wrote in his report that he had reviewed literature regarding Diffuse Idiopathic Skeletal Hyperostosis (DISH).
Moreover, Tribus’ repeated statements that he formed his opinion based on a “generic approach” to DISH injuries does not explain the “methodologies and principles” underlying his opinion in this specific case. Further, though Tribus stated in his opinion that “the literature demonstrates” that DISH patients could suffer severe consequences from slow falls, his testimony reveals that he could not identify any piece of “literature” upon which he relied to form this opinion. That calls into question the reliability of his conclusions. The Court cannot determine if the “literature” on which Tribus relied is sufficient because Tribus does not identify that literature.
Joellen Gill
The Defendant contended that Gill is not qualified as a chair designer and cannot opine about the chair’s design.
Gill never opined about how the Defendant could remedy the alleged hazards of the chair by changing the physical design of the chair. Gill did opine about possible warnings that the Defendant could have used to reduce the risk inherent in the design, using her knowledge of human behavior. But the presence or absence of a warning label has nothing to do with the physical design of the chair. Gill did not opine on chair design, so whether she is qualified to opine on chair design is irrelevant. Because the Defendant provided no other basis for exclusion, the Court denied the Defendant’s motion to exclude with regard to these opinions.
The Defendant also argued that Gill did not consider any facts outside of the Plaintiff’s counsel’s version of events.
Gill’s opinion is that the Plaintiff’s decision to sit on the chair arm was foreseeable human behavior. Gill elaborated in her deposition that her “opinions are focused on were the actions that were engaged in by this person who was injured, were they consistent with foreseeable human behavior. And, in this case, somebody sitting on the arm of a chair to facilitate a conversation is—it was certainly foreseeable behavior.”
The Plaintiff’s state of mind or motivations—that is, why he chose to sit on the chair arm—are not encompassed in Gill’s opinion about whether the decision to sit on the arm of a chair is foreseeable human behavior. So the Plaintiff’s decision-making process and whether that decision-making process was impaired by his intoxication are not relevant to Gill’s opinion that his actions were consistent with the foreseeable behavior of an outdoor chair user.
Held
- The Court granted the Plaintiff’s motion to exclude portions of Dr. David Jones’ opinions.
- The Court denied the Defendant’s motion to exclude portions of Dr. Russell Dunn’s opinions.
- The Court granted the Defendant’s motion to exclude Dr. Clifford Tribus’ opinions.
- The Court denied the the Defendant’s motion to exclude Joellen Gill’s opinions.
Key Takeaway
The expert must explain how that experience leads to the conclusions reached, why that experience is a sufficient basis for the opinion, and how that experience is reliably applied to the facts.
Case Details:
| Case Caption: | Scanlan V. Adams Manufacturing Company |
| Docket Number: | 2:22cv586 |
| Court Name: | United States District Court, Wisconsin Eastern |
| Order Date: | February 24, 2026 |
Leave a Reply