Here is a video, the corpses and their limbs twitch in convulsions, this happened with dozens of corpses.
You should submit your issue to carmageddon.com/bugger. Happened for me too in this exact same level and run into a strange bug in checkpoints stampede... I got 6 checkpoints, I used replay mode then an AI got the other checkpoint and then no checkpoints respawn anymore on the map, anywhere. So I started to waste other AIs but once I wasted them, they didn't respawn. So after wasting all of em', I couldn't finish the race coz there was nothing left to do. Also, I couldn't steal the checkpoints when wasting opponents, it worked with the first one wasted and stopped working for the next ones.