In this case I would not see running/walking away as cowardly. By staying or making a scene he will continue filming you and therefore possible having film of you doing some action you may later regret or at least could be edited to make you look like you're in the wrong. It's also unlikely you would actually get the camera footage from the camera man. I think the best course of action would be to contact a local law enforcement officer and then proceed with a court case if you didn't like the out come of that or wanted to pursue getting the video footage. Really though if you just walk away I think they camera man would just leave you alone.