Why am I choosing to go with the image of CNN getting it wrong and stating on-air that the individual mandate portion of the ACA had been struck down, and not Fox News, who did the same thing? Because from Fox News it's expected that they'd giddily jump to the anti-Obama conclusion, pounce without reading the entire ruling and not mind deliberately misleading their audience of aging, resentful reactionaries. CNN should've done better.
On the plus side, given CNN's ratings lately there's a pretty good chance no one saw this screw-up.
Adding: Great quote on this from Mother Jones: "CNN has its 'Dewey defeats Truman' moment. Fox News just has a moment."