Details of the incident involving a rapid response paramedic and a supporting two-person ambulance crew, which happened over the weekend, have just emerged.
According to the Ambulance Service, the paramedics were responding to an emergency call about a man complaining of chest pains when another man in the house became agitated.
He tried to stop the patient being moved and headbutted a paramedic who, along with a colleague, had to restrain the man while the patient was taken to the safety of the ambulance.
When the man was released, he followed the medics out to the garden and tried to assault them again - prompting them to call for police assistance.
The man who attacked them was taken into custody and the patient was taken to hospital for tests.
One of the paramedics suffered injuries to his shoulder and arm and was unable to continue with his shift, while a second paramedic ended up with a black eye and a cut to his face.
He returned to his duties after a short break and was later called to Ballymena PSNI station to attend to a patient -and by coincidence, it was the man who had given him the black eye.
"The PSNI, realising that he had been the victim of the earlier incident, suggested that it might be more appropriate for another crew to attend," an Ambulance Service spokesman said.
"But in a display of model professionalism, he saw fit to put his personal feelings to one side and deal with a patient presented to him."
But the NIAS is again calling for more steps to be taken to ensure their staff do not have to work under threat or fear of physical or verbal attacks.
"We would further seek that any person found guilty of such behaviour against our staff face the toughest of penalties available to the judiciary," the spokesman added.