Simon,
Is there no charge though about proceeding through an intersection (past the white solid line) before the car ahead of you has completed their turn?
In driver training they make this safety fact very well known.
It happens ALL the time but I definitely know it's a bad idea and leaves you in a vulnerable position.
For example you sometimes see these retards backing up on the road because the light turned green in the other direction and they couldn't clear it in time because too much oncoming traffic was running yellow/red lights in their direction. Or they are riding the bumper of the car in front of them to make it through before the light turns green in the other direction pressuring the car in front to maybe turn too early before cars who were running the yellow/red have cleared the intersection.
I am glad there is an officer actually charging for this offense (although he maybe should have charged you a different offense, I don't know what it would be called, but I know it's dangerous and wrong). This is just one of the many reasons you see so many accidents at controlled intersections.