As greyhound trainer Allen Christiansen returned to the dais area in front of the main grandstand following a race about 6pm he encountered Marshall who began to yell abuse and threaten him.
"You got beat, you f******g piece of s***" and "**** come here I will smash your head in," Marshall bellowed.
Christiansen continued to walk with his dog with Marshall following, continuing to shout abuse.
Herbert then crossed a roped fence, approached Christiansen and began yelling abuse while gesturing toward him in a threatening manner.
A small scuffle broke out when others got involved while several people continued to abuse Christiansen.
Others stepped in to ensure the disturbance didn't descend into physical violence and Christiansen walked away without responding to any of the commotion.
The end of the incident was captured on CCTV operated by the TAB.
In its decision, the Racing Integrity Board said the footage was broadcast live to the nation on Trackside television but the TAB said this was not correct.
Open Justice approached TAB to obtain the footage but was told it would not release it and that it never went to air because Trackside crossed to another race meeting.
The racing board investigator confirmed he viewed the footage as part of his investigation and that the board had a copy of the recording, which was provided by the TAB.
After the incident that day, Christiansen scratched the rest of his dogs from the meeting and left the course stating he didn't feel comfortable remaining.
The board noted there was relevant background to the fracas.
In July 2021 Christiansen assaulted Marshall's son Kyle, by slapping him through the open window of a vehicle and then slamming the door hard enough to cause the glass to smash.
He shoved a second man into a concrete wall, causing a cut to the back of his head and pushed another in the shoulder.
Christiansen was found guilty of three misconduct charges and disqualified for a period of three months, beginning in January 2022.
Both Marshall and Herbert admitted a charge of misconduct and were referred to an Adjudicative Committee to decide their penalty.
The committee said aggravating factors included the threatening and intimidating behaviour which happened in a highly public area.
"Their conduct fell well short of the behaviour that is expected of persons licensed to participate in the Harness Racing Industry and fell well short of what is reasonably expected of persons conducting themselves in society in general."
Mitigating factors included both men admitting the charge, their cooperation with the board and Marshall had apologised in writing and offered to take part in mediation.
Both men were fined $1000.
