That was a damned professional cop. And the driver was a dick. What gets me is that Johnny clearly looked like he was wanting a "alright, thanks," for not citing him, which I probably would have offered up and is a huge deal for a trucker. When the guy kept being a dick I bet he was probably pretty pissed off he didn't write him. Notice that he said "enjoy that violation free MCS inspection," bit his lip and slammed the door.
And I'll also throw out that since he was driving a big ass truck he probably fired off the air horn, and a lot of cops will write you for that. At first I thought it was a normal car horn, but the trucker horn makes a world of difference.
Lastly, cops are usually exempted from the cellphone law.