For a photographer who understands principles of how light works in photography, a notion of "incorrect" lighting does not exist. That is a sense that if a particular lighting setup (which could be not a setup at all, but something provided by the nature) fits the best an artistic conception, it has a right to exist. So, the lighting is there to create a mood and to add to the semantics of the photo, which allows to interpret "correctness" much wider than it used to be accepted in traditional commercial photography. On the other hand, whatever lighting solution you choose, it should look intentional and contribute to the harmony of the final photo.