While the defect in manufacturing is one that the producers did not mean to, a manufacturing defect is one that can be claimed as product liability case. Re-Statement (Third) of Torts stipulated that product liability refers to the products that have a manufacturing defect when the product deviates from its intended design in spite all possible care is applied during the preparation and marketing of the product.

A sample of a manufacturing defect is a vehicle’s braking system that does not function properly that result to the accident met by the plaintiff. Although the manufacturer of the vehicle did not mean for the brakes to fail, the strict liability rule in product liability law makes the manufacturer legally responsible.

The plaintiff may have the difficulty in proving that the product had caused the injuries of the plaintiff. For instance, if the car had some defect in its braking system, it could also be the driver’s poor reaction to driving situations could have been the real cause of the accident. Furthermore, there are some instances that it is difficult for the plaintiff to show that a defect has caused the accident because of the damage to the product. The car may be severely damaged during the accident that it is not possible anymore to prove what really caused the accident to happen.

There are some occasions when the plaintiff can depend on the “malfunction doctrine” to prove his case. Under this doctrine, if the circumstances of the accident show that a defect has caused the accident and the plaintiff can provide evidence that can eliminate other causes, then, the plaintiff can show causation even if the product is destroyed or severely damaged. This doctrine is the same with the application to res ipsa loquitir in the negligence law.