Witness memory is not actually very reliable, despite how much it is used in court. People remember things differently than they happened or can't remember them at all. In some cases, during a traumatic experience, a witness can make a crucial error.
For example, a man was once arrested and charged with rape. A woman who had been assaulted looked at a lineup and picked him out.
However, the man said it couldn't have been him because he'd been on TV. He was doing a live discussion. He said that there were other witnesses who had been part of the discussion, and there was a huge TV audience. The police did not believe him at first, scoffing at his claims.
The man was correct, though, and he had been on TV. In fact, the woman who had been raped was watching him speak when the real attacker approached her. When asked about it later, she simply remembered his face and not her attacker's. She was correctly remembering that she'd seen the man when she was being attacked, but she had simply forgotten the context—or gotten confused during a traumatic time—and blamed the wrong person.
Though the man was eventually cleared of any wrongdoing, this case shows just how incorrect a witness can be, and it's very important to keep this in mind during a court case, as incorrect memories could put the innocent behind bars. If you've been accused and you think that the witness is simply wrong in those accusations, make sure you know all of your legal options in California.
Source: Visual Expert, "Eyewitness Memory is Unreliable," Marc Green, accessed April 28, 2016