I don't think he was making stuff up. I think cops are taught to cite "the bird" as an improper traffic signal.
Check your state's drivers manual.. the one you study for the driving test..
Left turn, arm fully extended, level to the ground.... Right turn, arm bent at 90 degrees, pointing up. Caution or Stop, arm extended and pointing down, at a 45 degree angle..
I believe it's the standard in every state..
Please note: It says nothing about how you use your fingers.. just the positions of the arm..
Any police dept. that "teaches" their officers to cite drivers for "improper use of fingers" while making a hand signal is in error.. and in violation of state law...
A good lawyer will make mincemeat out of this officer, and his department.. he may be able to make the case that the driver's "civil rights" were violated..
The officer's actions may cost the department and the state several thousand dollars at the least, and several million in a worst case scenario..
It is stupid and unprofessional of an LEO to let personal feelings get in the way of doing a proper job..
Officers that let something minor like getting flipped off bother them, will inevitably be the same officer that decides he is judge jury and executioner in a child rape case or something highly emotional..
And if he makes that decision and mistakenly "punishes" an innocent person for that crime, where is your defense then?
Officers must remain in control, and civil at all times.. even when being screamed at, and insulted...
It comes with the job description and is part of their training..
At least it was when I was doing it..