Also known as: mistake of material fact · material fact mistake · mistake of fact
Written by attorneys · grounded in primary & secondary sources — see below
2 senses
An erroneous belief about a fact that, if true, would mean the defendant lacked the culpable mental state required for a material element of the offense. The defense succeeds when the mistake negates purpose, knowledge, recklessness, or negligence.
An erroneous belief about a fact that, if true, would mean the defendant lacked the culpable mental state required for a material element of the offense. The defense succeeds when the mistake negates purpose, knowledge, recklessness, or negligence.
Melissa Mills, a security guard, confronted an intruder on property she believed belonged to her employer. The intruder was in fact privileged to enter under a court order unknown to Mills. Because the intruder's privilege rested on a reasonable mistake of fact not caused by Mills's fault, Mills remained privileged to defend herself against the resulting confinement.
An erroneous belief about an existing fact that affected specific terms of a contract or donative document. When proved by clear and convincing evidence, the error permits reformation to match the parties' or donor's actual intention or supports rescission.
Michelle Murphy's will left her entire donor-advised account at Helping Hands Fund to a charity. She maintained two accounts under different emails but referred to them collectively in planning discussions. Clear and convincing evidence showed the omission of the second account resulted from a mistake of fact in expression, so the court reformed the will to include both accounts.
An erroneous belief about an existing fact that affected specific terms of a contract or donative document. When proved by clear and convincing evidence, the error permits reformation to match the parties' or donor's actual intention or supports rescission.
Each sense below has its own examples, sources, and questions.
A mistake of fact is a defense when it negates the purpose, knowledge, recklessness, or negligence required for a material element of the offense. If the defendant honestly believed facts that would make the conduct lawful, the prosecution cannot prove the required mental state beyond a reasonable doubt.
No. An intentional entry onto land possessed by another remains a trespass even when the entrant acts under a reasonable mistake of fact, provided the mistake was not induced by the possessor.
Maurice Marshall executed a trust that omitted a remainder interest he had repeatedly stated he intended to create for his niece. Extrinsic evidence proved by clear and convincing evidence that a mistake of fact in expression caused the omission. The court reformed the trust instrument to include the intended remainder.
Mustafa Mahmoud sold Miranda Morales a cow both parties believed was barren. After the sale, the cow delivered a calf, revealing it was fertile. Because the mutual mistake concerned a material fact about the subject matter, Morales could avoid the contract.
Marco Marquez contracted with Morgan Financial for aluminum at a price escalated by the Wholesale Price Index. Both parties assumed the index would track actual non-labor production costs. When the index diverged due to market changes, the mutual mistake of fact regarding the index's behavior permitted reformation of the pricing formula.
Reformation requires clear and convincing evidence that a mistake of fact or law affected specific terms and that the donor's actual intention differed from the written text. Direct evidence of intention contradicting the plain meaning may be considered.
Yes. When both parties to a sale share an erroneous belief about a material fact such as the subject matter's essential quality, the buyer may avoid the contract.
…refuse to execute it, or he may avoid it after it has been completed, if the assent was founded, or the contract made, upon the mistake of a material fact,—such as the subject-matter of the sale, the price, or some collateral fact materially inducing the agreement; and this can be done when the mistake is mutual. 1 Benj. Sales, §§ 605, 606;…