Speeding Ticket for 91, was actually going 72. (WV)

I got pulled over and the cop said he clocked me going 91 in a 65. He wrote the ticket for 84 as a “favor”. I was going 72. I checked my dash cam, it doesn’t show my speed, but based on the time it took me to go .2 miles (I can see the mile markers in the video) I was going 72 when he pulled me over. My speed was between 68-72 prior to being pulled over.

I feel like this blatant discrepancy can’t be legal. My neighbor said they had a similar experience with the same department.

Is there anything I can do other than just fight it? Should I get a lawyer?

Location: West Virginia.

Author: TelephoneDifficult27