Traffic Lights, Signs and Controls: Discrepancy Between Pull Out Reason and Ticket Description

My question involves a traffic ticket from the state of California

The violation code is 1 VC-21655.5B-1

I was driving on HOV lane of a two-lane ramp entering high way with my baby in car.

There are two lanes: one is HOV lane and the other is not. I was pulled out for not stopping on traffic light.
I told officer, I let the car from non-hov lane go first, and thought it's my turn now.
Officer then give me tickets, and make notes:"not obeying traffic lights."

I got mail in notice, stating my choices.
I click "request court appearance - ARRAIGNMENT" and send back with $490 check.
(can anyone explain what does this mean?)

Today, I searched my case online, and found the description to the code is
"FAILURE TO OBEY PREFERENTIAL LANE-HIGH OCCUPANCY".
I called court, and clerk told me, "it means I have only one person but drive on HOV Lane".
But, this is not true.

What should I do in this situation? Should I got a laywer? Any recommendation?

Traffic Lights, Signs and Controls: Discrepancy Between Pull Out Reason and Ticket Description