TV shows exist for the sake of getting people to watch them. Of course, if there is a scandal or something else that will really draw the attention of the masses, it will increase the views of the show. More views means more money, so I believe the exposure was completely intentional by one of the parties involved.
Actresses gain fame and notoriety from this kind of publicity, which can then boost thier career. Hardly anyone knew who Kim Kardashian was until she leaked a sex tape, and now she has several hit reality shows behind her and is known by her name and face all around the globe.
Yes, Charlotte McKinney's exposure in Malibu was intentional. Many celebrities will tend to do stuff like this just to get their names in headlines so they can hold on to their fame. It appears as if McKinney was doing exactly that, and it is unlikely she was unaware that paparazzi with cameras were nearby.
There's no easier way to get one's name in the media than by exposing a body part expected to be kept covered and she probably had the whole event carefully choreographed and planned out. How else would the media have caught it? It is becoming rather common for even the most established stars to flash a little flesh for attention. Madonna has done it through her career and who can forget Prince's cheekless pants at the AMA's one year or the infamous Janet Jackson "Nipplegate" fiasco? She will get the publicity she deserves and life will go on as normal for the rest of the world.