Limits of Expert Testimony

Posted in expert testimony on April 9, 2025

The Limits of Expert Witness Testimony in Jockey Truck Accident Case

A longshoremen at the Georgia Ports Authority in Savannah sued a truck manufacturing and operating company, alleging it failed to maintain and inspect a jockey truck operated by the plaintiff, resulting in his loss of control over the vehicle and serious injuries.

The plaintiff contended that the trial court erred in excluding expert witness testimony on the breach of the standard of care for maintenance of the truck.

Background

The defendant manufactures, maintains, and leases terminal tractors and trailers (commonly referred to as “jockey trucks”), which are smaller versions of tractor-trailers used almost exclusively to move shipping containers around terminal ports, such as the Garden City Terminal in Savannah. Typically, the stevedore company—which is tasked with loading or unloading a cargo ship and employs the longshoreman who perform those tasks—submits a lease request for the number of jockey trucks needed for a job and retrieves the vehicles from the defendant’s facility on site at the port.

On May 23, 2016, the plaintiff—who was working as a longshoreman for a shipping company at the time—went to the defendant’s facility and picked up a truck that had recently been serviced. He drove to a docked ship to receive his work instructions and was told to pick up a container from one berth and transport it to another. On the way, he hit a pothole in the road. As a result, the cab of the jockey truck tilted upward, separating from the chassis. With the cab now facing downward, he lost control and hit the brakes. But as he did, the truck pulled to the right, resulting in the towed trailer striking a cargo container on the side of the road.

After the collision, the plaintiff feared that a second container stacked on top of the one he’d just struck with the trailer might have become unstable from the impact and could possibly fall. So, with the cab of the jockey truck still detached and facing down, he backed the vehicle away from the cargo container and then climbed out the back. Soon other employees arrived and reported the accident; and several minutes later, the port police and the defendant’s representative also were on the scene. The plaintiff—who suffered serious injuries from the wreck—was transported by ambulance to the hospital. A subsequent inspection of the jockey truck didn’t find any mechanical defects.

The plaintiff sued the defendant, alleging that its failure to maintain and inspect the cab latching mechanism and the brakes of the truck the plaintiff was operating amounted to negligence and resulted in him losing control of the vehicle and suffering serious injuries. The defendant filed an answer and subsequently moved for summary judgment, arguing the plaintiff failed to produce any evidence of a defect in the or that the defendant had any knowledge of any defect. The plaintiff supported his response by filing the affidavit from a mechanical engineer with experience in the design and development of specialty trucks such as motor homes, ambulances, and terminal trucks. Specifically, the expert opined that the accident was a result of the jockey truck’s cab latch and the brakes failing to function properly and that this failure could have been prevented if the defendant had properly inspected and maintained the vehicle.

The defendant deposed the plaintiff’s expert and, thereafter, filed a motion to exclude his affidavit and expert testimony in its entirety, arguing that he wasn’t qualified to offer opinions on the design, function, or maintenance of jockey trucks, and that his opinions weren’t the result of any discernible methodology. The plaintiff filed a response and a second affidavit from the expert that addressed the arguments on his qualifications and experience. After the trial court held a hearing on the defendant’s motion to exclude and its motion for summary judgment, it took both issues under advisement.

A few months later, the trial court issued an order partially granting and partially denying the defendant’s motion to exclude the testimony of the plaintiff’s expert. Specifically, the court ruled that the expert was qualified to testify regarding the jockey truck’s cab latching mechanism and to offer his opinions on how the latch could’ve failed mechanically, thus resulting in the plaintiff’s accident. However, the court also ruled that the expert’s opinions pertaining to the jockey truck’s brakes were excluded, concluding that they were summary in nature, and his methodology on that point lacked evidentiary support. Importantly, the court further ruled that the expert’s qualifications and experience were insufficient to permit him to offer opinions as to whether the defendant’s maintenance and inspection routine for either the jockey truck’s cab latching mechanism or its brakes failed to comply with the industry standard of care.

In addition, the trial court issued an order granting the defendant’s motion for summary judgment. Principally, the court ruled that the defendant had met its burden of showing that it exercised ordinary care to ensure the jockey truck was in safe condition; and without the plaintiff’s expert’s testimony, the plaintiff failed to establish a genuine issue of material fact as to whether the defendant’s maintenance and inspection of the vehicle failed to comply with the standard of care. Consequently, the court determined summary judgment was warranted.

the Decision of the Court of Appeals

Presiding Judge Stephen Dillard wrote that O.C.G.A. § 24-7-702 (“Rule 702”) concerns the “admissibility of opinion testimony by expert witnesses in civil cases.” And the standard for the admissibility of such testimony is “found in Rule 702 (b), which provides:

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify thereto in the form of an opinion or otherwise, if:

  • The expert’s scientific, technical or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
  • The testimony is based upon sufficient facts or data;
  • The testimony is the product of reliable principles and method; and
  • The expert has reliably applied the principles and methods to the facts of the case.

Judge Dillard stressed that the issue of the admissibility or exclusion of expert testimony “rests in the broad discretion of the court, and consequently, the trial court’s ruling thereon cannot be reversed absent an abuse of discretion.” Indeed, the Supreme Court of Georgia has explained that “the whole premise of Rule 702 is that a trial court must act as a ‘gatekeeper’ to ensure the relevance and reliability of expert testimony.” And as a gatekeeper, the trial court “must assess both the witness’s qualifications to testify in a particular area of expertise and the relevancy and reliability of the proffered testimony.”

Importantly, the Eleventh Circuit Court of Appeals describes this assessment as a “rigorous three-part inquiry” in which the trial court considers whether:

  • The expert is qualified to testify competently regarding the matters he intends to address;
  • The methodology by which the expert reaches his conclusions is sufficiently reliable as determined by the sort of inquiry mandated in the U.S. Supreme Court case Daubert v. Merrell Dow pharmaceuticals, inc.; and
  • The testimony assists the trier of fact, through the application of scientific, technical, or specialized expertise, to understand the evidence or to determine a fact in issue.

While there’s inevitably some overlap among the basic requirements—qualification, reliability, and helpfulness—Judge Dillard said that they remain distinct concepts and the courts must take care not to conflate them.

Furthermore, the burden of establishing the reliability of an expert’s opinion falls on the proponent (in this case, the plaintiff) who’s required to show that his proffered expert testimony is based upon sufficient facts or data and is the product of reliable principles and methods, which the expert applied reliably to the facts of the case.

Here, the trial court noted that the plaintiff’s expert was a licensed mechanical engineer, and as his affidavit indicated, he was familiar with the design and mechanisms of jockey trucks similar to the vehicle involved in the subject accident, including the cab latching mechanism. And while the court ruled that the expert’s background and experience qualified him to provide causation opinions on how the cab latching mechanism could have failed, it also ruled that nothing in his background showed that he had any experience as a mechanic or sufficient knowledge as to how the defendant mechanics, or port mechanics generally, perform their maintenance and inspection responsibilities. As a result, the court ruled that the expert wasn’t qualified to offer opinions as to the standard of care required of such mechanics or that they breached such standard. In doing so, the trial court properly fulfilled its role as gatekeeper, Judge Dillard concluded.

The defendant submitted evidence of the jockey truck’s two inspections, with neither indicating that the vehicle wasn’t functioning properly. Specifically, the report completed the morning before the accident indicated that the truck was tested for more than two hours to ensure it was functioning properly. Also, the defendant’s corporate representative testified that the company’s mechanics are regularly required to perform an 18-point inspection checklist before returning vehicles to service, which includes a check of the brakes, and that failure to do so could result in termination of employment.

But rather than establishing that a recognized standard of care required the defendant to do more, the plaintiff’s expert merely opined that the cab latching mechanism and brakes should’ve been inspected but likely weren’t. As a result, he failed to articulate a reliable standard of care either through his own experience or that of others in the specific profession applicable to the situation at issue. In fact, the expert didn’t even try to do so.

When engaging in a reliability analysis, courts “must be careful to focus on the expert’s principles and methodology, not on the conclusions that they generate.” Critically, as in this case, when a witness “relies solely or primarily on experience, then the witness must explain how that experience leads to the conclusion reached, why that experience is a sufficient basis for the opinion, and how that experience is reliably applied to the facts.” Indeed, Judge Dillard explained that if admissibility could be “established merely by the ipse dixit of an admittedly qualified expert, the reliability prong would be, for all practical purposes, subsumed by the qualification prong.” Given these circumstances, the trial court didn’t abuse its discretion in finding that the expert’s experience was insufficient to allow him to offer reliable opinions on the standard of care required of the defendant’s maintenance mechanics.

Additionally, when an expert’s opinion is based partially on speculation, this goes to the weight of the testimony rather than its admissibility, the judge explained. And it’s likewise true that the appropriate standard for assessing the admissibility of the opinion of an expert isn’t whether it’s speculative or conjectural to some degree, but whether it’s wholly so. Nonetheless, an expert “may not render an opinion that is wholly speculative or conjectural.” And here, in addition to the expert’s lack of experience as a mechanic, he could only speculate that because the accident occurred, maintenance and an adequate inspection on the jockey truck must not have been conducted. Furthermore, as the trial court found, the plaintiff’s expert’s opinions as to how the jockey truck’s brakes failed were similarly speculative, offering a conclusion—untethered to any discernible methodology—that they needed to be adjusted. As such, Judge Dillard and the panel of the Court of Appeals found that the trial court didn’t abuse its discretion in excluding the plaintiff’s expert’s opinions concerning the maintenance and inspections of the jockey truck’s cab latch and brakes.

The Court concluded that the plaintiff’s allegations that the defendant’s mechanics failed to comply with the standard of care for the inspection and maintenance of its jockey trucks involved specialized matters beyond the ken of ordinary laypersons. However, without his expert’s opinions (which were properly excluded), the plaintiff failed as a matter of law to show any breach of duty caused by a deviation from any appropriate standard of care in the situation at issue here. As a result, the Court of Appeals affirmed the trial court’s rulings partially excluding the plaintiff’s expert’s opinions and granting summary judgment in favor of the defendant. Johnson v. Terminal Inv. Corp., 2025 Ga. App. LEXIS 60 (Ga. App. February 19, 2025)

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