Accident Reconstruction Expert’s Opinions About Visibility and Conditions at the Scene of the Accident Admitted
Posted on July 17, 2025 by Expert Witness Profiler
This case involves a rear-end collision between Plaintiff Tyler Brown’s sedan and a sprinter van driven by Defendant Nikolay Muzyka.
The accident occurred during the early morning hours of July 29, 2021. Defendant Muzyka, who was driving in the far right lane, began to slow down as he saw lights from emergency vehicles ahead. As he was slowing down, Defendant moved over two lanes into the far left lane. Plaintiff Brown, who was driving in the far left lane, collided with Defendant causing both cars to turn facing oncoming traffic.
Brwon sued Muzyka for negligence and negligence per se. Brown also sued Aleksei Dulepin—the owner of the sprinter van—and Amload, LLC—Muzyka’s employer. Defendants retained accident reconstructionist, Andrew D. Irwin, as Defendants’ testifying expert. Plaintiff filed a motion to preclude Irwin from offering certain opinions at trial.
Accident Reconstruction Expert Witness
Andrew Damien Irwin is an Accident Reconstructionist with Aperture (formerly Scientific Analysis Inc). He uses his decades of experience to provide expert testimony, making use of aids such as accident site diagrams, maps, charts, and crime scene exhibits.
He holds a Bachelor of Science in Architectural Engineering from the University of Texas at Austin and has completed specialized study in accident reconstruction at Northwestern University and Texas A&M University.
Irwin is a member of multiple professional societies, including the National Association of Professional Accident Reconstruction Specialists (NAPARS), Society of Accident Reconstructionist (SOAR), Texas Association of Accident Reconstruction Specialists (TAARS), the American Society of Mechanical Engineers (ASME), and the Society of Automotive Engineers (SAE).
Discussion by the Court
Plaintiff asked the Court to prohibit Irwin from offering two categories of opinions. First, Plaintiff argued that Irwin should not be allowed to give his opinions about Plaintiff’s reaction time, considering the visibility and conditions at the time of the collision. Second, Plaintiff asked the Court to preclude Irwin from offering his opinions about Section 545.157 of the Texas Transportation Code, known as Texas’s “Move Over or Slow Down” law.
Irwin’s Opinions about Visibility and Conditions at the Scene of the Accident are Admissible
Plaintiff Brown objected to Irwin’s opinions that at the time of the accident “visibility was good” based on an aerial video of the location of the collision taken during the day, roughly two years after the accident.
Brown argued that because this accident took place around one o’clock in the morning on a dark stretch of highway, Irwin’s opinions are incomplete, irrelevant, misleading, and will cause unfair prejudice if the opinions are based on an illustration of the accident scene that was taken during daylight hours.
Brown also argued that Irwin’s opinions that there was sufficient visibility for Plaintiff to see and react to the sprinter van’s taillights or flashers and avoid a collision are unsupported speculation and merely Irwin’s subjective belief because Irwin did not perform a looming threshold analysis.
Analysis
Plaintiff did not point the Court to any cases holding that the failure to use a looming threshold analysis renders an accident reconstructionist’s testimony unreliable. Defendants argued whether Irwin relied on some incorrect facts or should have examined additional or different data is a valid subject of cross-examination, but it did not render Irwin’s opinions inadmissible. The Court agreed with Defendants.
Irwin’s failure to perform a looming threshold analysis to account for the “dark-lighted” conditions at the time of the accident similarly concerned the weight of the evidence, not its admissibility. The fact that Irwin’s conclusions might be based on data or assumptions that are contracted by facts in the police report did not render Irwin’s conclusions inadmissible.
Irwin’s Opinions do not Constitute Impermissible Legal Conclusions
Plaintiff argued that Irwin offered incorrect opinions about Texas’s Move Over or Slow Down law, which impermissibly invaded the province of the judge and jury.
What Plaintiff failed to mention is that Plaintiff’s counsel asked Irwin whether Defendant Muzyka followed the Move Over or Slow Down law. In other words, Irwin did not comment on or opine about the law in his expert report.
While Irwin is not permitted to offer legal conclusions at trial, the Court held that the opinions contained in his expert report did not constitute impermissible legal conclusions.
Held
The Court therefore denied the Plaintiff’s motion to limit the opinion testimony of Defendant’s expert Andrew D. Irwin.
Key Takeaway:
The reliability of the data and facts underlying Irwin’s opinions concerned the weight of the evidence and is subject to cross-examination. In other words, it did not serve as a basis for excluding Irwin’s ultimate opinions.
Plaintiff may cross-examine Irwin about whether his failure to use a looming threshold analysis to determine Plaintiff’s perception at night or whether any of the factors he did not account for materially affect his opinions.
These factors concerned the weight of Irwin’s expert testimony, not its admissibility. The Court found that while Plaintiff may cross-examine Irwin as to these alleged deficiencies, Plaintiff has not established that Irwin’s opinions are unreliable and therefore inadmissible.
Case Details:
| Case Caption: | Brown V. Muzyka Et Al |
| Docket Number: | 6:23cv474 |
| Court Name: | United States District Court, Texas Western |
| Order Date: | May 22, 2025 |
