Ergh that sucks x_x if it's any consolation I remember reading somewhere something about how you're unlikely to get eaten by a shark unless they're starving to death or you look like something they would eat normally (apparently surfers look kind of vaguely like seals enough to fool a shark from the bottom?) or you're bleeding.
The phone sunset pic is pretty nice! Bodes well for the camera shots :D
I'm not sure what sharks think, how or why they do what they do other than that they are out there just living their lives like any other animal; but I do know that I'd rather not die in the jaws of one of them. As with other comments here, a human going into their domain must surely know and accept the risks so that young chap who chose to go there, and paid a price for it, is no exception. Too bad for his family I guess, they didn't make that choice.
I'm looking at the images currently...not the best I've ever taken, might be a couple of reasonable ones out of the 100+ I took.