Nothing will change that she was speeding. There's no loop hole that says, "If a police officer commits a crime while pursuing you for your crime, then its a get out of jail free card."
You can pursue the officer's actions and make his job a living hell, if thats the route you wanted to go. This is of course if you can prove he did exactly what your girl said he did.
If you can prove that he didn't shoot her with the gun and that she wasn't speeding, just like any other speeding ticket, then you can get out of it. I would have asked to see the radar reading in the car and the log to verify that I was doing the speed he said. The officer might have visually pulled her over for speeding and you can try to dispute this sort of procedure but police officers are visually certified by the state to observe the speed of cars.
This seems to be a rumour on online boards that officers don't show all the time. I know it happens, but personally knowing officers they have informed me that a police officer should always show up to his court day because its scheduled on one of his 'court days'. Any and all trials the officer has to show at are scheduled on this date so he can appear.
If luck were on his side the officer wouldn't show, but the safer bet is to talk to the prosecutor and plea the ticket down. I don't know how it is in Cali but I know in Jersey you can plead a speeding ticket down to an unsafe driving that will be a fine but no points on insurance. Jersey also has a $250 surcharge that they tack on top of the fine for unsafe driving... I'll be getting that little bundle of joy 6:30pm tomorrow night as luck would have it. (I was speeding 15mph over and the officer gave me careless driving to cut me a break so it was a 2point ticket rather than a 4point. I'm going to plea it down to unsafe driving which will cost me zero on insurance but about $500 out of pocket. I'm allowed to plea down to unsafe driving twice, the third time the points come back. This is Jersey of course)