Res ipsa loquitur is an exception to the general negligence rule, and it permits a party to infer negligence, as opposed to affirmatively proving it, when certain elements are met. In order for the doctrine to apply, traditionally a party must show:
(1) the event must be of a kind which ordinarily does not occur in the absence of someone’s negligence
(2) the event must be caused by an agency or instrumentality within the exclusive control of the defendant; and
(3) the event must not have been due to any voluntary action or contribution on the part of the plaintiff.
The state has incorporated these three elements into its pattern jury instructions.It also requires the defendant to have superior knowledge of or be in a better position to explain the accident for res ipsa loquitur to apply. Once the elements of res ipsa loquitur are met, the burden shifts to the defendant to show that something other than its negligence caused the accident. Whether sufficient evidence supports an inference of negligence under res ipsa loquitur is a question for the jury; however, the district court must first determine whether sufficient evidence has been adduced at trial to support the consideration of a res ipsa loquitur instruction and therefore whether the instruction should be given . . .
We have previously stated that the comparative negligence statute renders certain common law complete defenses inapplicable. Specifically, we have recognized that the comparative negligence statute subsumes the doctrines of assumption of the risk and last clear chance. In these cases, we acknowledged that a plaintiff may still proceed in the underlying negligence suit, and the common law defenses cannot bar the suit, provided that the plaintiff’s negligence does not exceed that of the defendant. Otherwise, these doctrines would subvert the principles of comparative negligence and would compel results inconsistent with the plain language of NRS 41.141 . . .
To completely bar plaintiffs from the use of res ipsa loquitur in situations where comparative negligence applies contravenes the express language of NRS 41.141. Accordingly, we conclude that NRS 41.141 operates to subsume the third element of res ipsa loquitur. From this point forward, the third element of res ipsa loquitur is revised to provide that the doctrine may apply as long as the plaintiff’s negligence is not greater than that of the defendant. On this point, we expressly overrule the test for res ipsa loquitur as stated in Bialer v. St. Mary’s Hospital in favor of the one stated in this opinion. The doctrine of res ipsa loquitur is to henceforth reflect the impact of comparative negligence and NRS 41.141.