"Reading all the papers of the previous trial in London I can't understand why I have been sanctioned, especially this hard," Troicki said.
The tribunal ruling published by the ITF described the doping control official, who had 15 years' experience in her work, as "conscientious and cautious" in giving evidence.
"Her response was that this was not a matter upon which she could advise the player," the tribunal panel said.
Trociki, however, was described as "confident and determined" though "someone prone to exaggeration in order to make his point."
The tribunal reduced Troicki's ban from the standard two years for a first anti-doping violation because it accepted he was stressed by illness on the day and his long-standing needle phobia.
Troicki was suspended in July ahead of the U.S. Open, and his ranking has fallen to No. 69. He peaked at No. 12 in June 2011.
If the ban is upheld, Troicki will be sidelined for five more Grand Slam events plus the Davis Cup final next month when the Novak Djokovic-led Serbs host the defending champion Czech Republic in Belgrade.