I had a similar situation with a Mustang right after I got my license, only I pulled over. The cop came up to my car and said something along the lines of, "He initiated the race, he drove recklessly, and you won't do this again if I let you off. Get out of here." Then being the asshole I am, I flipped off the guy in the Mustang as I pulled away. I was actually dropping a friend off so I had to pass again and the Mustang driver was in cuffs.