I don't really care, in another context I'd be upset but paparazzi are scum, no one deserves to be treated like celebrities are treated by paparrazi, followed around wherever you go with them just waiting for you to slip up or step into poop so that they can sell their disgusting "work" for lots of dollars.
Even if you argue that celebrities made a choice and have to live with paparazzi (something I don't agree with!), Sean Penn's son did not choose his parents but apparently he has to live with it anyway.
Paparazzi are like the asshats in school who won't stop poking others and just wait for them to explode so that they can claim "I did nothing, I just poked him a little bit and he punched me in the face", no one can or should be blamed for flipping out sooner or later, it's inevitable in some situations.
What makes this worse is that this is probably the best day of the month for this paparazzo, he's not a victim, he got exactly what he wanted, footage that's worth something. Celebrity and son walking from a to b is nothing, son of celebrity hurling slurs is news and the video suddenly in demand.
His choice of words was obviously not the best but he's a teenager in a very difficult situation. I don't want to know what I would have said at his age if people had shoved camera's into my face constantly. I think it's unfair to label him a short tempered, entitled asshole based on a little bit of footage filmed under circumstances no one of us has ever been in.