He said there were two officers in the car when the man approached and allegedly told one of the officers he had a gun and was going to kill him. As he advanced on the officer he was concealing something in his sweatshirt pocket.
Mr Hoyle said the officer backed off from the man, warning him several times to show his hands and that police were armed, before the officer fired the single shot.
Eastern District police spokeswoman Kris McGehan confirmed yesterday the man was not armed.
The Independent Police Complaints Authority has been advised of the shooting and a criminal investigation will be run by senior police officers from outside the Eastern District.