Testimony of Mechanical Engineering Expert Witness Rejected, Complaint Dismissed

Testimony of Mechanical Engineering Expert Witness Rejected, Complaint Dismissed

Plaintiff Nathan Cottrill (“Plaintiff” or “Cottrill”) filed a lawsuit against Defendant Tricam Industries, Inc. (“Defendant” or “Tricam”), alleging product liability and breach of implied warranty.

Nathan Cottrill, a Best Buy Geek Squad employee, went to a client’s house on December 22, 2019, to mount two Sonos 5 speakers in an indoor basketball court. To carry out the installation, Cottrill utilized a ladder manufactured by the Defendant, a GLMPX-26 articulating ladder (“accident ladder”). After successfully ascending and descending the accident ladder twice, Cottrill proceeded to climb it for a third time, standing about 11 to 12 feet off the ground. Unexpectedly, he fell to the ground. According to Cottrill, the accident ladder was bent near a rivet point.

Cottrill stated that Mechanical Engineering Expert Witness, Kurt Whitling had identified the manufacturing defect that caused his fall.

Whitling authored an expert report on October 19, 2021, following his inspection of the accident ladder on September 15, 2021, twenty-two months after the incident. Whitling’s findings indicated that the failure seemed to have originated at a rivet hole on the left side of the ladder, proceeding almost entirely through the U channel. Additionally, he noted that the rivet hole was oblong in shape, and the oblong portion extended beyond a section of the U channel that measured 1/16” thick, into an edge that was 1/8” thick.

Tricam filed a motion to exclude Whitling’s opinions, along with a motion for summary judgment.

Tricam also filed a motion to exclude opinions contained in Kurt Whitling’s second and third Reports. Oral argument was held on October 19, 2023, during which Plaintiff withdrew Whitling’s second and third reports. The Court, therefore, denied as moot Defendant’s motion to exclude opinions contained in Kurt Whitling’s second and third Reports.

Mechanical Engineering Expert Witness

Kurtis G. Whitling is a mechanical engineer with experience in forensic engineering, and product design. Whitling has work experience in a wide range of fields and prides himself in applying sound engineering principles in every investigation.

Discussion by the Court

In addition to inspecting the ladder, Whitling stated that he reviewed the manual for the Gorilla Model GLMPX-13-17-22-26 and the technical specifications for that ladder from the Gorilla Ladder website.

Finally, Whitling articulated the following conclusions “to a reasonable degree of engineering certainty” based on his inspection and review:

  1. At the time of the accident, Cottrill’s weight was much less than the ladder’s rated capacity of 375 pounds.
  2. Cottrill properly set up the ladder as an extension ladder at the time of the accident.
  3. Gorilla Ladders modified the hole in the left U channel portion of the ladder in order to install a rivet for the cross brace piece due to some unknown manufacturing issue. By modifying the U channel, the hole protruded into the thicker portion of the U channel. This significantly weakened the U channel and caused a large stress concentration in that area. Gorilla Ladders’ modification to the U Channel caused the failure of the ladder.
  4. When Cottrill attempted to climb the ladder, the weakened U channel cracked, then twisted. The failure threw Cottrill from the ladder and caused the injuries.

Motion to Exclude the Opinions in the Whitling Report

Tricam asserted the following arguments in support of its motion to exclude the opinions in the Whitling Report: (1) the report did not comply with the requirements of Federal Rule of Civil Procedure 26(a)(2)B); (2) the report provided insufficient evidence to show that Whitling was qualified to offer his opinions; and (3) the opinions in the report were not based on a reliable methodology.

Should Mechanical Engineering Expert Witness’ Report be Excluded Under Rule 26(a)(2)(B)

Tricam argued first that the Court should exclude Whitling Report from evidence because it did not set forth Whitling’s “experience or purported qualifications” and did not attach “a CV, rate sheet, or testimony list” as required under Federal Rule of Civil Procedure 26(a)(2)(B). In response, Cottrill explained that he had received both the Whitling Report and a separate document containing Whitling’s CV and testimony list in August 2021, but that his counsel had inadvertently failed to forward the document containing the CV and testimony list to Tricam when he served the Whitling Report. Here, the Court found that Cottrill had met his burden to show that his failure to timely disclose Whitling’s CV, rate sheet, and list of prior testimony was a harmless violation of Rule 26(a)(2)(B).

Whether Mechanical Engineering Expert Witness is Qualified to Offer His Expert Opinion

Tricam argued that Whitling lacked the necessary qualifications because “there is no evidence that he has ever designed, tested, manufactured or assessed ladders for purposes of defect or causation.”

In opposition, Cottrill noted that Whitling was a mechanical engineer and a registered professional engineer in Ohio. He explained that “the cause at issue here is two pieces of aluminum which were fastened by a steel rivet and that failed and pulled apart,” and asserted that this was an issue any engineer would be qualified to assess. As to specific experience relevant to Whitling’s opinions, Cottrill highlighted Whitling’s past work at a defense-oriented engineering firm and his asserted expertise in testing and analysis, origin and cause, and critical fastening – bolted joint failure analysis. The Court found the evidence sufficient to demonstrate that Whitling was qualified to offer an opinion as to whether a manufacturing defect was evident from a ladder with an elongated rivet hole.

Whether Mechanical Engineering Expert Witness Used a Reliable Methodology

Tricam argued that visual inspection was insufficient to support Whitling’s opinions, including his opinion that Tricam “modified the hole in the left U channel portion of the ladder . . . due to some unknown manufacturing issue.” As to this opinion, Tricam noted that Whitling did not, for example, compare the accident ladder to an exemplar or design drawings to confirm what “unknown manufacturing issue” spurred the contemplated modification to the hole. As to Whitling’s additional opinion that a modification to the rivet hole “significantly weakened the U channel and caused a large stress concentration in that area,” Tricam further argued that Whitling did not perform calculations to determine the stress concentration or assess the increased amount of stress caused by the modification.

The Court concluded that there was too great an analytical gap between Whitling’s stated findings and observations and his ultimate conclusions as to causation. His testimony was based on visual observations without calculations or testing and lacked comparison to design drawings or other ladders to explain and support his conclusions.

The Court granted the motion for summary judgment that Tricam filed before dismissing Cottrill’s complaint.


The Court excluded the testimony of Mechanical Engineering Expert Witness Kurt Whitling for being unreliable. Then, the Court dismissed Cottrill’s complaint.

Key Takeaways:

  1. Importance of Evidence Support: Tricam emphasized the necessity for comprehensive evidence supporting expert opinions. The Court deemed visual inspection alone insufficient to validate Whitling’s conclusions.
  2. Analytical Gap Concerns: Tricam raised concerns about the analytical gap between Whitling’s observations and his ultimate conclusions regarding causation. The Court emphasized the need for a clearer connection between the evidence presented and the conclusions drawn.
  3. Exemplars and Design Comparisons: Tricam highlighted the absence of comparisons between the accident ladder and exemplars or design drawings to confirm assertions regarding manufacturing issues. This suggests that thorough comparative analysis can strengthen expert opinions.

Case Details:

Case Caption:Cottrill V. Tricam Industries, Inc.
Docket Number:5:22cv72
Court:United States District Court, Ohio Northern
Citation:2024 U.S. Dist. LEXIS 44842
Order Date:March 14, 2024


Leave a Reply

Your email address will not be published. Required fields are marked *