Ashley Gill-Webb went on trial in London, five months after the incident took place on Aug. 5.
The 34-year-old Gill-Webb is accused of using an old ticket to get into the stadium and then shouting at Bolt, "Usain I want you to lose. Usain you are bad," followed by an obscenity.
After a plastic beer bottle was thrown onto the track, Dutch judoka Edith Bosch — who was sitting in the same section of the stadium — intervened and pushed Gill-Webb in the back.
"He was shouting specifically at Usain Bolt ... he repeated these taunts over and over, it went on and on for about two minutes," Bosch said in a statement read to Stratford Magistrates' Court.
After confronting Gill-Webb, Bosch recalled saying "Dude, are you crazy?"
"He was trying to walk away so I pushed him hard to stop him," she added. "I was angry with what he had done, which was so disrespectful."
Bolt won the gold medal in 9.63 seconds. The Jamaican said after the race he was unaware of the bottle-throwing incident.
Gill-Webb denies using threatening words or behaviour with intent to cause harassment, alarm or distress.
His lawyer said Gill-Webb cannot remember throwing the bottle because he was suffering from a "manic episode" at the time.
But prosecutors said Gill-Webb, from the northern English city of Leeds, knew what he was doing.
"He passed through several steps waving an old ticket in front of people to get past security and that was a deliberate act," prosecutor Neil King said. "He thought, 'I want to get into the Olympics and I will do it by waving this ticket and it worked.'"
Since the incident, Gill-Webb has lost his job and received psychiatric treatment.
The case was adjourned until Jan. 11.