Mr. Ewell never actually shares his side of the story in court in To Kill a Mockingbird. He takes the stand, but he only speaks in short, angry outbursts and avoids answering direct questions. He refuses to elaborate on his accusations against Tom Robinson and instead relies on prejudice and insults.
The lack of a detailed account from Mr. Ewell's perspective is a key element of the story. It highlights the lack of evidence against Tom Robinson and emphasizes the prejudice and ignorance that fuel the accusations against him.