---
title: "Engineering Expert Qualified to Opine on Crossbow Malfunction"
meta:
  "og:description": "The fact that the engineering expert did not conduct his own testing does not disqualify his opinion or render it unreliable"
  "og:title": "Engineering Expert Qualified to Opine on Crossbow Malfunction"
  author: "Expert Witness Profiler"
  description: "The fact that the engineering expert did not conduct his own testing does not disqualify his opinion or render it unreliable"
---

# Engineering Expert Qualified to Opine on Crossbow Malfunction

Posted on April 30, 2025 by Expert Witness Profiler

Scott and Melanie Campbell (“Plaintiffs”) brought this case against Ravin Crossbows, LLC and Velocity Outdoor Inc. (collectively, “Defendants”). This case arises from personal injuries sustained by Plaintiff Scott Campbell (“Scott”), an experienced hunter.

On November 9, 2022, Scott was hunting from a ladder stand using a Ravin 10 Crossbow, manufactured by Ravin Crossbows. He attempted to shoot a deer, but the arrow fell a few feet away, and he fell from the stand, sustaining injuries. Scott had successfully used this crossbow multiple times before and understood its instructions and warnings.

Scott’s injuries included a displaced intraarticular fracture of the distal radius with significant comminution of the dorsal and volar cortex. He also had signs of post-traumatic acute carpal tunnel syndrome.

Plaintiffs’ expert, [Craig Clauser](https://expertwitnessprofiler.com/expert-witness/Craig-Clauser/1510894), an engineering expert, opined that the incident was a result of a derailment of a bowstring on the crossbow. In other words, Clauser believed that the accident happened because the bowstring came out of the groove at the end of the cam. Plaintiffs’ theory of liability hinges upon Clauser’s expert testimony.

Defendants filed a motion to exclude the testimony of Craig Clauser under _[Daubert](https://www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;opi=89978449&amp;url=https://www.law.cornell.edu/wex/daubert_standard&amp;ved=2ahUKEwjti4fhqP-MAxVoyzgGHW-hJMYQFnoECDcQAQ&amp;usg=AOvVaw3SYCMPiihxmj_61iFPw7QQ)_, challenging his qualifications and the reliability of his opinions.

## **Engineering Expert Witness**

[Craig David Clauser](https://expertwitnessprofiler.com/expert-witness/Craig-Clauser/1510894) is a metallurgist and materials engineer by training. As part of his work experience, Clauser was responsible for employee safety and training and failure analysis investigation which is relevant to the instant matter. Clauser is also a member of various professional societies and has contributed to the ASM Handbook on Failure Analysis and Prevention.

[Want to know more about the challenges Craig Clauser has faced? Get the full details with our Challenge Study report.](https://expertwitnessprofiler.com/order/add?eId=1510894&amp;pId=2)

## **Discussion by the Court**

### **A. Qualifications**

Defendants argued that Clauser should be excluded because he lacks the practical experience within the hunting industry necessary to make a reliable opinion about liability and causation. The Court disagreed.

Clauser, after all, possesses skill or knowledge greater than the average layman in determining engineering issues. He need not have academic training in hunting to have an expert opinion on matters related to engineering.

Defendants may prefer Clauser to be an expert in hunting and crossbows, but the law does not require that.

### **B. Reasoning and Methodology**

#### **1. Causation and Liability**

Defendants argued that Craig Clauser’s opinions lacked sound methodology, were speculative, and failed to meet reliability requirements, specifically pointing to his lack of mathematical calculations, drawings, or diagrams to test the reliability of his reasonable alternative designs.

The Court found that Clauser’s opinions on causation and liability were reliable. His conclusions were based on a detailed, independent review of the physical crossbow and evidence like the broken arrow shaft as well as the “witness marks” left on the shaft of the crossbow as the arrow traveled up the crossbow, which the Court deemed a generally accepted and reliable method in engineering analysis, supported by “good grounds” and not mere speculation.

#### **2. Proposed Alternative Designs**

Defendants contended that Craig Clauser’s proposed alternative designs were speculative and unreliable because he did not conduct testing, calculations, or provide a concrete design for them, arguing this lack of rigorous methodology made his opinions inadmissible.

The Court evaluated the reliability of each proposed design separately. Regarding the cam with increased groove depth, the Court held that this opinion was reliable. The Court determined it was based on Clauser’s engineering expertise and detailed analysis of the physical crossbow involved in the incident, including microscopic examination and analysis of witness marks, which provided “sound reasoning and good faith grounds” despite the absence of testing on a modified component.

In contrast, the Court held that the opinion regarding cam shields or removable guards was unreliable. This proposal was deemed speculative by the Court, lacking any basis in testing, analysis of feasibility or potential dangers or evidence of existing designs on the market. A cam shield might have helped reduce the risk of injury but there is nothing to show that it would be a reasonable alternative design to the Ravin 10.

#### **C. Assistance to the Trier of Fact**

Defendants argued that Craig Clauser’s testimony should be excluded because he performed no testing or analysis to determine the root cause of the incident and failed to test his alternative designs, contending that this lack of empirical work meant his testimony would not provide relevant information to assist the jury.

The Court found that Clauser’s opinions will assist the trier of fact.

The Court’s reasoning was that Clauser’s testimony pertains directly to the alleged injuries Scott Campbell suffered, the potential causation, and the issue of liability. His specialized knowledge is relevant to determining the nature and extent of Scott’s alleged injuries in relation to the crossbow incident.

## **Held**

The Court granted in part and denied in part Defendants’ motion to limit the testimony of expert [Craig Clauser](https://expertwitnessprofiler.com/expert-witness/Craig-Clauser/1510894).

## **Key Takeaway:**

A cam shield might have helped reduce the risk of injury but there is nothing to show that it would be a reasonable alternative design to the Ravin 10. Additionally, there is no evidence that a cam shield exists on any current or past crossbow on the market, and Clauser did not prepare or present an actual design with a cam shield.

Thus, it is apparent to the Court that Clauser’s opinion that a cam shield or removable guard is a reasonable alternative design lacks the requisite reliability for it to be admissible under _Daubert_.

## **Case Details**

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