How To Prove A California Bilateral Mistake Defense

In California, a defense of Bilateral Mistake is defined as:
A bilateral mistake occurs when both parties to a contract, whereby each operates under a misconception about a contract and its terms.
It simply means:
When both parties to a contract have the wrong understanding of a material fact.
There are 2 elements of the defense:
- Element 1. Both parties in a lawsuit were mistaken about an issue material to a contract. In a lawsuit, both sides misunderstood an important part of their agreement, which can be used as a defense to show that the contract should not be enforced because neither party had the correct information when they made their deal.
Facts that might support this element look like:
* Both parties believed the property in question was zoned for commercial use, but it was actually zoned residential.
* The seller and buyer both assumed the contract included all fixtures, but the seller had removed several items prior to closing.
* Both parties were unaware that the property had a significant structural defect, which was not disclosed during negotiations.
* The contract specified a delivery date that both parties mistakenly thought was feasible, but unforeseen circumstances made it impossible.
* Both parties relied on outdated market data, leading them to misjudge the fair market value of the property involved in the contract. - Element 2. The defendant would not have agreed to enter into the contract had defendant known about the mistake. The defendant wouldn’t have signed the contract if they had known about the mistake, meaning they didn’t fully understand what they were agreeing to, which is a key part of claiming a bilateral mistake in a legal dispute.
Facts that might support this element look like:
* The defendant was unaware of the significant error in the contract terms that misrepresented the value of the goods involved.
* The defendant had previously expressed a clear preference for a different pricing structure, which was not reflected in the final agreement.
* The defendant relied on the representations made by the plaintiff, which were later proven to be inaccurate and misleading.
* The defendant would not have proceeded with the contract if they had known the true nature of the mistake regarding the delivery timeline.
* The defendant had a history of avoiding contracts with similar discrepancies, indicating a consistent approach to due diligence.
(See California Civil Jury Instructions (CACI), No. 331.)
If you’re in court without a lawyer and plan to assert a Defense of Bilateral Mistake, having a Personal Practice of Law at Courtroom5 is essential. You’ll need to make informed decisions about what to file at each phase of your case and prepare legal documents supported by thorough legal research and a strong analysis of the facts. Equip yourself with the tools and knowledge to effectively navigate your legal journey.
Prove Your CA Bilateral Mistake Defense
U.S. Civil Cases Only