Report it.
Having said that, funny enough,I clicked on your thread assuming it would be a cyclist RLJing and nearly hitting a pedestrian. Maybe that reflects the fact that we, as a group, must do it at least 10x as often as drivers. At some junctions you can see a dozen do it one after the other.
I'd say report it and make sure that a report is filed. We had a doctor over here in LA that had the habit of swooping in front of cyclists and than break checking them, i.e. slamming on his brakes forcing them to do the same to avoid colliding with him.
The last time that he did this it was against two cyclists who were (if I remember correctly) finishing up with an organized ride. Their only real "crime" was that they were riding two abreast on "his road" as well as they were traveling at the posted speed limit at the time.
One of the cyclists got some serious road rash, the second crashed through the rear window almost cutting his nose off as well as loosing several of his teeth. The good doctor than called 911 and stated to the 911 operator that he wanted to teach the cyclists a "lesson." Because he had done the same thing to several other cyclists there was a paper trail that eventually lead to his conviction, and he is now warming a jail cell.
So, even if they can't prosecute (for whatever reason) at least you will have either started, or added to a paper trail that will hopefully lead to a conviction somewhere down the road.
