Lou
When I was much younger, I got more than my share of speeding tickets.
Of course I tried to talk my way out of them or politely asked the officer if he could give me a break, etc. I never said that I wasn't guilty, if I was guilty as I figured that would just piss off the officer.
In this case, I know that the pickup was going faster than me as he passed me and then applied the brakes as he changed lanes and cut in front of me. I am relatively sure that the officer's view was limited so he probably did not see the pickup therefore he assumed that I was the one speeding. I feel that I had no choice but to plead not guilty. The judge may, or may not agree with me but at least I will have my chance in court.
What really got me was the officer saying to me that the radar told him that I was the one speeding. My impression was (and you have confirmed this) that the radar will pick up the fastest moving vehicle or possibly the speed of the biggest vehicle. In this case, both were the dual-wheel pickup.
Wayne