See the problem with copyright is that it doesn't fit easily into any predefined areas of law. Copyright wasn't a legal concept until relatively recently.
There are two main concepts lawyers have to deal with when considering copyright; authorship and originality. And defining those terms has been the difficulty, as a sizeable amount of conflicting case law has come about. Basically, copyright belongs to the author once you can establish that there is an author and who that author is. Courts have had different thresholds down the years towards acknowledging whether a person is an author or not, but we have meandered to the extent where generally speaking the person who presses the shutter is considered the author, even if he had nothing whatsoever to do with the composition.
Some as usual oppose this viewpoint, because they find it highly silly. But at the same time copyright is a complex legal animal and if it were easy to appease everyone then it would have been done by now. In this case, how can you argue that someone who's composed a shot, arranged to have it taken, provided the equipment and let someone else press the button be considered the author? The alternative argument is the scientific; it is the person who's pressed the shutter who's created the image at the formation point.
Like I said, copyright is a flabbergasting thing. You can for instance spot a photographer taking a photograph, mimic his exact actions, and arrive at virtually an identical picture, but there would be no infringement unless you copy his picture.
For further reading try to find the case regarding Creation Records. Bearing in mind it involves the Gallagher brothers it should be fun reading anyway.
And somewhat off tangent because this is more originality related than author related, look for the Bridgeman Art Library case as well. Those two are probably major reading for the field of copyright at the moment, even though they are some years old now.