Speeding Tickets: CVC 22349(A), 80 in a 65

My question involves a speeding ticket from the State of: California

I was driving on the northbound 15 on December 26, 2009, meeting friends for dinner. I was in no rush to meet up with them since they are consistently late.

As I recall, I was driving in the #2 lane (one closest to the fast lane) the entire time. As I was driving a guy cut me off and continued into the fast lane doing at least 100MPH. Shortly thereafter, flashing lights were in my rear view mirror. I continued at my pace thinking the officer was going to switch to get the other guy but realized he was following me so I began switching to the right shoulder.

The first thing he asked me was "Do you know how fast you were going?" and I gave him an honest "I don't know" since I rarely speed and my car can't handle speeds in excess of 75. He told me I was doing 80 and asked me if I knew the speed limit, I answered 65 on this stretch and up north its 70. He then asked if I was tired because he saw me swerving which is why I caught his attention, I was puzzled because I don't recall swerving at all, so I told him no I don't remember swerving and thought I was driving straight. The officer asked for my papers and I gave it to him. He came back later with the ticket for 80 in a 65. I quickly glanced and the ticket and noticed he didn't mark how he got my speed, he only circled Max Spd in the P.F/Max Spd box. I asked him if he got me using radar and he said no, he used something with his bumper and I was swerving in the #3 lane, then switched into the #2 lane to pass slower moving traffic and that's when he got me.

He didn't right on the ticket how he got me, does he have to? There's no other notes, I've been told that this is easily defeated since the officer hasn't written anything. I was planning on just taking it and doing traffic school but if I could avoid all of it, I'd rather do that. I wasn't planning on fighting it since it's the officer's word over mine, but if he has to write down how things happened and he didn't I'll use that.