The person, a male, was charged by Harness Racing New Zealand over an action deemed to be detrimental to the interests of harness racing.
It was heard by the Judicial Control Authority for racing.
The defendant's employer had asked that neither his nor the defendant's name be made public.
HRNZ did not object.
"Not naming the person was to protect his employer from any adverse publicity.
"We also considered it was a stupid action on the part of the person concerned," Edward Rennell, the general manager of HRNZ, said.
Disqualification will prevent the person entering a racecourse or undertaking any licensed activities.
Evidence was given at the hearing in Christchurch on March 4 that the person was in a corporate area on the inside of the track about 40m from the finishing line.
Near the end of the race he was waving his arm and threw the pen into the field of horses.
It landed about 12m from the pylons marking the inside of the track and about 25m from the winning post.
Racecourse inspector Barry Kitto said had the pen struck a horseman, horse or sulky, the effect could have been profound.
The pen weighed 17g-18g.
The person was spoken to by a security guard and escorted back to the corporate area. He contacted the authorities when the matter received publicity and admitted the breach.
He said he was excited as the horses neared the finish.
"As they went past me I was basically jokingly making out I had lost money on the race and foolishly drew a pen from my pocket.
"I meant to pretend to throw the pen by raising my hand behind my back in a throwing motion.
"I intended to drop the pen behind my back."
He said it was prank that went horribly wrong and an act of drunken stupidity.
He said he had consumed approximately 10 330ml bottles of lager during the day.
He described his condition as "merry but not intoxicated".
Russell McKenzie (chairman) and P. J. Rosanowski, who heard the charge, accepted that alcohol was the likely explanation of the behaviour.
"The committee finds part of the defendant's explanation to be not entirely credible but there is nothing to suggest his actions were deliberate or that he intended to inflict any harm on any horse or horseman."
Trainer Phil Williamson has given way to his son, Matthew, as the driver of Springfield Sam in the $85,000 Yearling Sales Trot for 2yr-olds at Ashburton today.
Phil drove Springfield Sam to win at Addington last Tuesday when the gelding was having his first start.
Matthew drove Diedre's Flash to win the Yearling Sales Trot for the Williamson stable at Addington last May.
Matthew (19) became the youngest driver to win a Harness Jewels race when he partnered Leighton Hest at Ashburton in May as an 18-year-old.
Matthew's brother, Nathan, in his first season as a trainer, has Latheronwheel and Lewis H in the Yearling Sales Trot.
He will drive the latter, a Sundon-Sound Of Chiola gelding.
Lewis H is a brother to Martina H, winner of the Dominion Handicap and Rowe Cup, and Tony H (NZ Hambletonian and Yearling Sales Trot for 3yr-olds).
Lewis H, a trial winner at Winton last Wednesday, is having his first start.
He was a $55,000 buy at the premier yearling sale.
Latheronwheel, a half-brother by Continentalman to The Fiery Ginga, has been placed in his two starts.
Paramount Gee, unbeaten on four starts, is well placed from barrier two to lead throughout the mile.
