It was sickening to watch the ESPN commentators trying to justify Serena's behavior. Her own coach admitted he was coaching during the match. The rule is quite clear. He violated it. Her beef was with him, not the umpire. Her point apparently was that she didn't see him, so she didn't receive any coaching. Her real point was that she is Queen Serena and a different set of rules should apply to her, kind of like the NBA applies to LeBron and a few other stars.
She has been a great player but she is a horrible role model.