A more thorough explanation:

The concept of “reasonable reliance” is often used in the tort of fraud. It means that a person who claims to have been harmed by another’s false statement must prove that they were justified under the particular circumstances in believing that the statement was actually true.

For example, if someone sells a car and says it has never been in an accident, the buyer may rely on that statement when deciding to purchase the car. However, if the buyer later discovers that the car was in fact in an accident, they may not be able to sue the seller for fraud if it was not reasonable for them to rely on the seller's statement. If the buyer had the opportunity to inspect the car and see that it had been repaired, it may not be reasonable for them to rely on the seller's statement that it had never been in an accident.

During a civil trial, the jury will decide based on the evidence whether or not a plaintiff’s reliance on a defendant’s statement was reasonable under the circumstances of the case.