Talk to a lawer(they really do have good advice, they spent years in school studying the subject), take it to court, supeana the officer and have the cop explain his BS to a judge.
Any vehical, even tractors and bicycles, can use the fast lane during the course of a manuver such as a left turn. They are not to remain in the fast lane but they can use it.
It's kind of the same principle as passing someone, it is legal to exceed the speed limit while passing because it reduces your time in the oncoming lane and is nessesary to pass at period, in many cases.