The video is gone now.
http://www.nbclosangeles.com/news/local-beat/Knotts-Berry-Farm-Rollercoaster-Accident-Injures-Guests-59751017.html
http://www.youtube.com/watch?v=EGJGl4SfKCg&feature=channel
Secondly, I'm not sure if you are completely correct in your understandings of the mechanics of a rocket coaster. At about 13 seconds into the video, if you watch the child's seat, it is jarred abruptly, shifting it to the right, and up. That either implies the integrity of the train is compromised, or that there was a force that caused it move. Did the train roll over the cable perhaps on the return trip?
Suprised this video is still up!