Double Car Pullover, Not Racing

So my friends were following me home from an event, i had my car and another had his, and another had hers, so three cars in all. I was in front of the pack, and i merged to the other side of the freeway quickly to get on another onramp to another freeway, my friends followed, the officer followed, One of my friends kind of split away, so it was only two of us left. The officer followed us long enough to know that we were together then decided to pull both of us over, we both got speeding tickets for 80, what i want to know is that unfair becuase the officer wasnt even in full view of my car nor i dont think he could have caught my speed, he would have to assume my speed by the last car in the group, which i think i could fight that in court, and suggestion or someone to tell me im wrong or right, thank you

That is allowed; he can use his judgment but of course if you think you can show he was wrong, take it to court.