I laughed a bit when you said why in the heck would he lie to me??? Many times, officers are out for DUI and Drug patrol, and they are looking for any minor offense (such as minor speeding, light over you plate out; not signalling for 2 seconds) to pull you over. This gives them the "in" to further their investigation-- they then look for additional signs (smell of alcohol, smell of marijuana, nervous behavior) to further investigate.
Check your speedometer, make sure it is working--
Unless it is for the principle of the matter, your ticket will probably be reduced-- it probably isn't worth paying an attorney $1000 for an $82 ticket.