Mass Tort Blog

Proof of Use v. Proof of Injury in Mass Torts

Mass tort cases require two types of evidence: proof a client used a product and proof they were injured.

A tort is an act or omission other than a breach of contract that causes injury or harm to an individual and constitutes a civil wrong that allows courts to impose liability. Torts fall into three general categories:

  • intentional tort
  • negligent torts
  • strict liability torts e.g., liability for making and selling defective products.

Product liability imposes liability on parties along the chain of manufacture of any product. This includes the manufacturer, wholesaler, and retail store owner. Product liability can fall under negligence, strict liability, or breach of warranty.

Under a negligence claim, four elements must be proved. They are as follows:

  1. Duty- refers to whether there was a duty of care which is an obligation to either do or not do something that will harm someone else;
  2. Breach- plaintiff must prove that the defendant had a duty of care and failed to uphold the required standard of care;
  3. Causation- the defendant’s actions had a direct consequence to the plaintiff’s injuries; and
  4. Harm- it can be non-economic like pain and suffering or extreme emotional distress or injury to a person’s body, to a family member or to property.4

Additionally, the New York Court of Appeals also added that for strict product liability for design defects to prove a prima facie case the plaintiff must show that the manufacturer breached its duty to market safe products. In civil cases, the plaintiff has the burden of proving his case by a preponderance of the evidence. Therefore, the burden of proof is met when the party with the burden convinces the fact finder that there is a greater than 50% chance that the claim is true.

Difference between proof of use and proof of injury

Proof of use under product liability refers to the plaintiff proving that they used the defective product that actually and proximately caused the plaintiff’s injury and as a result, it made the product unreasonably dangerous.5 The plaintiff must however make sure that they used the product in a way that the manufacturer intended consumers to use it.6

A manufacturer’s duty of care is to ensure that the products they offer are reasonably safe and to provide warnings of any potential problems that the product’s use may cause. As a result, a manufacturer’s duty of care extends only to a consumer who utilizes the product as intended and appropriately. The manufacturer may not owe a duty of care to a consumer who uses the product for a different purpose.

On the other hand Proof of injury speaks to providing evidence that because an individual used a defective product, they suffered financial losses and physical damages. In a personal injury case the burden of proof lies with the injured party to convince a judge or a jury that the person being sued is responsible for causing the injuries. The burden of proof is an evidentiary threshold and therefore evidence is needed to show that the defendant is responsible for the injuries and there exists a basis for an award of damages.

Importance of proving proof of use and proof of injury in a personal injury/ product liability claim

They are three types of defective product claims:

  1. Manufacturing defects- the plaintiff needs to show that the product was defective due to an error that arose when the product was being made;
  2. Design defects- If the plaintiff believes the product was correctly manufactured but the overall design was flawed, they will need to show that the dangers and risks created by the design were unreasonable; and
  3. Inadequate warnings or instructions- If a plaintiff can demonstrate that the product’s dangers and risks are not obvious to the average customer, they may have a case. Often, one can establish culpability by demonstrating that the product’s instructions and warnings were insufficient for the ordinary consumer.

For each of the aforementioned claims to be admissible in court, there are certain elements that a plaintiff must establish to prove a prima facie case for product liability; they are:

  1. The defendant sells a product that the plaintiff uses;
  2. The defendant is the commercial seller of such a product;
  3. The plaintiff suffers an injury;
  4. When the defendant sold the item, the item was defective; and
  5. The defect was an actual and proximate cause of the plaintiff’s injury.

Examining the elements to establish a prima facie case proof of use and proof of injury must be shown. It is also clear that when it comes to product liability claims it is insufficient to argue that a client was injured while using the defective product. An individual must also clearly demonstrate that their injury was caused by the defect itself.

Evidence needed to identify the subject product.

To prove the elements for a product liability claim, it is important to have the evidence needed to back up claims cited in a lawsuit.  Critical evidence includes:

  1. The defective product;
  2. Evidence that the manufacturer had knowledge of the defect, such as emails or memos;
  3. Medical bills and payroll records to account for a client’s financial losses;
  4. Photos and videos of injuries and the defect;
  5. Accident reports;
  6. Bystander and expert witnesses;
  7. Insurance documents such as the policy;
  8. Labels; and
  9. Marketing materials.

Is there a product liability case without the product?

The defective product is very important as it is the central cause of injury. A rather peculiar feature of product liability cases is that the event that gives birth to a claim for product defects frequently also destroys the key evidence in the case which is the defective product. Even if the product is not destroyed, the occurrence may do significant damage which leads to someone tossing it in the trash because they do not recognize its importance as evidence in a potential lawsuit.

In the case of Torres v Matsushita Electric Corp, where the plaintiff brought a claim against the defendant for design and manufacturing defects after the vacuum cleaner she owned caught fire, the District Court of Appeal of Florida, Fifth District held that recognizing that the only way the plaintiff could prove her case would be with the benefit of an inference that the malfunction was caused by a product defect, which the court declined to apply because the product was unavailable due to the negligence of the plaintiff or her lawyer. In this case, it is seen that where a plaintiff does not produce the defective product as evidence in court, it is less likely that their product liability claim will be successful.

On the other hand, other courts have taken a different approach, as was seen in the case of Murray v Traxxas Corp where a child was severely burned when vapors from a can of fuel were meant for use in a remote-controlled model vehicle ignited. The trial court, in this case, held that because the plaintiff had thrown away the fuel can that caused injury there was no proof to support the plaintiff’s theory, that the fuel can cause a flashback explosion and that the fuel contained in the can was the same as the fuel that had been present at the time of sale. 14

However, the Court of Appeal of Florida, Second District disagreed with this, stating that the fact that the fuel can could not be examined and tested did not impede the lawsuit. This is because the can was observed by eyewitnesses to the accident, it had been inspected and photographed by the fire inspector after the accident, and the shopkeeper who sold the fuel can be identified in a photograph as a Traxxas Top Fuel can. Furthermore, experts for both sides were able to review the available evidence and an exemplar of the can to reach opinions regarding the nature of the explosion, how the explosion occurred, and whether the incorporation of a flame arrestor in the design of the can would have prevented the accident.

Looking at this case, it can be seen that depending on the type of product liability claim brought forward the plaintiff need not produce the defective product in court for a claim to be successful.

For more education and training around what type of evidence is required in mass tort cases enroll in our Practice Management for Attorneys or Paraprofessionals course.

Written by Antoinette Muimi

Antoinette Muimi is an ambitious, adaptable, and committed law school graduate from Strathmore University in Nairobi, Kenya. In addition to her internship at The Mass Tort Institute, she has also interned at Bashasha and Company, a law firm based in Kenya and Uganda. She has previously served as Programs Lead at the United Nations Sustainable Development Network as well as Under-Secretary-General at the Strathmore Law Clinic.


Share on facebook
Share on twitter
Share on linkedin

More Posts

Scroll to Top