A report by the panel said the first complaint, from a business owner in Avondale, alleged Macdonald falsely implied the complainant engaged in criminal activity.
Macdonald was alleged to have sent emails about the criminal activity with images from the complainant's personal social media account to other council staff.
The second complaint, from a member of the public, alleged Macdonald abused the complainant while the complainant was walking his dog, the report said.
"You better watch yourself; I am sick of all that s*** you are spreading about me on Facebook", Macdonald allegedly said.
"This is my final warning ... you should look out for me ... you better be careful."
In the report, the complainant said the incident took place about 6.20am on March 6, and he was genuinely concerned at the nature and tone of the alleged threat.
In his response, Macdonald did not dispute what he was alleged to have said and believed he had done nothing wrong.
Macdonald claimed online activity by the complainant had led to his family receiving threats of violence at 3am.
"What does he expect?" Macdonald submitted in response.
"He seems to think it is right to make up lies and dish out personal abuse at community leaders and think that we have no right to ask him to stop.
"[Redacted] and his actions fall way below that expected of him and his peers," Macdonald submitted.
The panel also reviewed a third complaint, however Macdonald was found not in breach of the council's code of conduct for it.
