A cashier is not a cop. A cop has the authority to order you to perform actions within his power, one of which is to require your compliance to assist in completing the citation.if you're at a grocery store and you're rude to the cashier can they taze you? no, they can't. they have to deal with you the old fashioned way, by talking to you. this cop took the easy way out and abused his power
The cop does not have to humor anyone arguing about a ticket. The place for argument is in court, not on the side of the road.
The cop was in the right, mostly.