This is a product liability case arising from a motorcycle accident. Plaintiff Cameron Woodall alleged that on September 9, 2022, he was severely injured while wearing a motorcycle helmet allegedly designed and manufactured by Defendants Yohe Helmet Manufacturing Co., Ltd. and Foshan City Nanhai Yongheng Helmet Manufacturing Co., Ltd.; and distributed and sold by Defendant Cycle Gear.
Plaintiff claimed that the helmet was defectively designed and unreasonably dangerous because it failed to incorporate available anti-rotational technology, which allegedly would have mitigated the forces that caused his traumatic brain injury during the accident.
Defendant Cycle Gear maintained that Plaintiff’s cognitive and neurological impairments may be influenced, at least in part, by his history of marijuana use, as documented in his medical records.
In support of this theory, Defendant Cycle Gear designated Dr. Janyna M. Mercado, a neuropsychologist, to offer opinions regarding the potential relevance of Plaintiff’s prior substance use to his current condition. Mercado did not examine Plaintiff but reviewed his medical history and opined that substance use is a relevant pre-existing risk factor when evaluating post-injury impairments.
Plaintiff contended that Mercado’s opinions concerning his marijuana use are speculative, unreliable, and inadmissible under Rules 403 and 702.
Neuropsychology Expert Witness
Janyna Marie Mercado-Couch is a licensed clinical neuropsychologist who specializes in brain-behavior relationships and the effects of medical history on cognitive and emotional functioning.
She has extensive experience evaluating patients with traumatic brain injuries, and she routinely conducts evaluations of the kind at issue in this case.
Discussion by the Court
Admissibility Under Rule 702
Mercado is Qualified
Here, the Plaintiff did not dispute Mercado’s qualifications. Thus, the Court found that Mercado’s background, training, and clinical experience satisfy the qualification requirement under Rule 702.
Mercado’s Specialized Knowledge will Help the Trier of Fact
Defendant Cycle Gear sought to introduce Mercado’s opinion that Plaintiff’s history of marijuana use is a relevant factor in assessing his current cognitive and psychological impairments.
There is no dispute that Plaintiff’s medical records—including those cited in his Life Care Plan—contain repeated references to marijuana use, cannabis dependence, and related diagnoses. Mercado relied on these records, in conjunction with her clinical expertise and scientific literature, to conclude that Plaintiff’s substance use is a relevant pre-injury risk factor for cognitive dysfunction. Because Plaintiff’s current neurological and psychological symptoms are central to his damages claims, and because the proposed testimony provides context for evaluating alternative or contributing causes, the Court found that Mercado’s opinions would “help the trier of fact to understand the evidence or to determine a fact in issue.”
Mercado’s Testimony is Based on Sufficient Facts and Data
Mercado’s opinions are based on her clinical experience and review of Plaintiff’s medical records, and accepted literature in the field of neuropsychology. Plaintiff has not cited any authority suggesting that reliance on medical records in this context is improper.
Mercado’s Testimony is the Product of Reliable Principles and Methods Reliably Applied to the Facts of the Case
Mercado testified that she conducted her analysis in accordance with APA Ethical Standard 9.01(c), which permits forensic opinions based on record review and professional experience when direct testing is not performed.
She further acknowledged that while she cannot quantify the extent to which Plaintiff’s marijuana use contributed to his current symptoms, that limitation reflects the inherent boundaries of neuropsychological science and does not undermine the reliability of her methodology.
Admissibility Under Rule 403
Having found that Mercado’s opinions are admissible under Rule 702, the Court next considers whether they should be excluded under Rule 403.
In this case, Mercado’s opinions appear to be directly relevant to causation, damages, and the weight to be given to Plaintiff’s cognitive complaints. The fact that the topic may have prejudicial implications does not render it inadmissible, particularly where the testimony is grounded in scientific methodology and offered by a qualified expert. Accordingly, the Court found that Rule 403 does not bar admission of Mercado’s challenged opinions.
Held
The Court denied the Plaintiff’s motion to exclude certain opinions of Janyna M. Mercado, Ph.D.
Key Takeaway:
In fact, expert witnesses—particularly in medical or psychological disciplines—may base their opinions on a review of records without necessarily conducting an in-person examination.
Case Details:
| Case Caption: | Woodall V. Cycle Gear, Inc. |
| Docket Number: | 4:23cv870 |
| Court Name: | United States District Court, Texas Eastern |
| Order Date: | August 12, 2025 |
Leave a Reply