What is the burden of proving that the trial court erred?

Assuming the trial court erred, it is plaintiffs' burden is to establish that, in the absence of the asserted error, there is a reasonable probability of a different result. (Zhou v. Unisource Worldwide (2007) 157 Cal.App.4th 1471, 1480.) Plaintiffs' theory of prejudice is that the purported error likely caused the jury to conclude that an authoritative individual believed defendant's claim that he was not at fault for the accident, and found him not negligent as a result. This theory fails for three reasons.