If no one was hurt I would have kept going. Why wait for the speeding ticket. The Stang will most likely be sited for the skid marks where he broke free. You want to tell the police why that happened? If it was serious I would stop long enough to make sure everyone was ok.
I bet the guy in the stang would throw you under the bus when he tells his story. No one likes to take blame for crashing... always someone else, or faulty equipment.