What Is “Res Ipsa Loquitur” and How Does It Affect Personal Injury Claims?

Published in Personal Injury on August 11, 2015

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Res ipsa loquitur is Latin for “the thing speaks for itself.” The concept is commonly used in personal injury claims as a rule for the presentation of evidence, and in applicable cases, is often the only requirement needed to prove a defendant’s negligence.

When Is Res Ipsa Loquitur Used?

In a typical personal injury case, a plaintiff needs to prove through evidence that the defendant’s negligent actions caused injury. Circumstantial evidence, which uses logic to prove negligence instead of direct demonstration, allows courts to infer negligence and hold the accused accountable. In cases where no other cause could reasonably be to blame for injury, res ipsa loquitur can be used to effectively account for injury. The rule allows for common sense to dictate certain situations to determine negligence.

Res ipsa loquitur is most often used in medical malpractice lawsuits. When a patient experiences injuries that are only attributable to a healthcare provider’s negligent actions, his or her attorney may choose to use res ipsa loquitur to prove liability when there may not be other pieces of evidence to support the case.

The rule came about during an 1863 case, Byrne v. Boadle. A man was struck by a flour barrel that fell out of the window of a flour dealer’s shop. The man lost consciousness, and was unable to use direct evidence to prove his case. However, the court decided there was no way the barrel could have fallen without negligence on the owner’s part, and it was on him to prove his innocence rather than the plaintiff.

Proving Liability With Res Ipsa Loquitur

There are a few guidelines that must be established to prove liability using the res ipsa loquitur standard:

The plaintiff cannot present physical evidence regarding the negligent act.
The defendant has an understanding or means of getting evidence regarding the injury’s cause.
The injury would not have occurred if negligence was not a factor.
The plaintiff did not play a role in the injury.
The defendant owed the plaintiff a duty of care during the time when the plaintiff was injured.
The defendant was in control of the circumstances that caused the injury.

With these elements present, res ipsa loquitur will effectively shift the burden of proof to the defendant, who will need to prove that his or her actions did not cause injury. The plaintiff does not have to prove who was responsible for negligence – only that the negligent act happened.

The Use of Expert Witnesses

In some states, using expert witnesses in conjunction with res ipsa loquitur is frowned upon because if an expert’s opinion is required, then it follows that the issues surrounding the case are highly complex. An expert opinion may call into question the presence of negligence. However, states like Massachusetts hold that expert testimony and res ipsa loquitur can coexist in a personal injury claim.

Personal Injury and Res Ipsa Loquitur

Medical malpractice is the most common type of case where res ipsa loquitur is used, but it can also be used in other types of injury cases. For instance, if a consumer finds a dead rat in a box of pasta, the only reasonable explanation for the rat to be there is that someone was negligent during the packaging process. To understand whether res ipsa loquitur can be used in a given case, ask the following questions:

Is the accident that caused the injury only possible through negligence?
Was the defendant responsible for controlling whatever variable caused the accident and subsequent injury?

If you can say yes to both questions, then it is very likely that a court will approve the use of res ipsa loquitur. Invoking the rule does not end the case; it only establishes negligence. From that point, the case may revolve around proving whether the negligent act caused injury.

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