Because he's flat out saying that he knew the button wouldn't work as an excuse, so he lied and said it was the screen flickering. Lying for monetary gain is fraud. He's not saying that he had screen flickering. He's saying that he used it as an excuse to trick an Apple employee into giving him his way. And furthermore, he recommends that others should do the same thing.
That's fraud. Plain and simple. There was nothing really WRONG with his phone, but he wanted a different one, so he lied to get a replacement.