In dashcam footage played to the ACT Magistrates Court on Wednesday, Ivan Meyer, 56, can be heard yelling at the victim calling him "a cock-head".

"Five f---ing k's an hour, you f---wit," Meyer can be heard saying.

Meyer, who is retired and lives in Burra, NSW, previously pleaded guilty to common assault, negligent driving and property damage.

Agreed facts state at 10.50am in January 2023 the 82-year-old victim was driving in a multilevel carpark in Phillip with his wife in the passenger seat.

Meyer "became frustrated with the slow driving manner" of the man and tried to overtake by crossing onto the wrong side of the road, the document states.

As a result, Meyer hit the front right corner of the victim's car, causing minor paint damage, an indent, and a panel to come loose on the driver's side mirror.

Meyer then exited his car and walked up to the other vehicle "yelling obscenities and hitting the driver's side window with a large black torch".

When the victim rolled down the window, he was struck in the face with the torch causing a sore and bloody lip.

On Wednesday, defence lawyer Andrew Byrnes sought to tender a report written by a forensic psychologist which claimed Meyer had been suffering from caffeine intoxication at the time of the crimes.

Prosecutor Harry Wagner objected to this, saying there was a lack of medical evidence for the psychologist to form these conclusions.

Giving evidence to the court, the report's author said Meyer had been "using caffeine since around 2007 and has been likely in a state of caffeine intoxication since that time".

The psychologist stated Meyer had also been taking paracetamol, which may contain caffeine, for a broken tooth at the time.

She said Meyer had reported drinking 10 energy drinks a day, which was "excessive and beyond recommended levels".

Magistrate Alexandra Burt allowed to report to be tendered, but said the caffeine intoxication diagnosis was "tenuous" and did not provide much assistance to the court.

Ms Burt stated the victim and his wife would have been "rightfully terrified" during the road rage incident.

Speaking directly to Meyer, Ms Burt stated: "There are many frustrations in life and other people can't be harmed because you can't control that frustration."

She said the victim, who has recently been diagnosed with dementia, felt he could no longer drive and no longer support his wife in that way.

"[The victim] doesn't feel confident in the car anymore," Ms Burt stated.

Meyer was ordered to pay almost $1300 in compensation for damage to the victim's car, and for exploratory medical procedures the 82-year-old had as a result of the strike to the face.

Meyer was also sentenced to a two-year good behavior order and fined $800.

He will be required to attend anger management classes if assessed as suitable.