Victims' campaigner Willie Frazer believed a man who arrived at his home with a sympathy card had been sent by the Provisional IRA to threaten him, a court has heard.
Co Tyrone man Frank McGirr has been accused of hand delivering a sympathy card to Mr Frazer at his Markethill home and shouting "You should be dead you b******", before the pair fell to the ground in a physical struggle.
However, it was claimed at Armagh Magistrates' Court that McGirr, 63, of Shanliss Road in Stewartstown, had honestly believed that Mr Frazer had recently died and was delivering the card to his family.
McGirr denies making threats to kill and malicious communications.
Police were called to Mr Frazer's home in June 2015 after he got into a physical struggle with McGirr in his front garden.
A video incident was captured on Mr Frazer's security camera.
Giving evidence to the court Mr Frazer said he was in his house getting ready to go to church when he heard a heavy rapping on the front door. When he opened it, a man - whom he later discovered was McGirr - shook his hand and then gave him a sympathy card.
"He then said something like 'you should be dead you b******'. I threw the card down and asked him to leave my premises," Mr Frazer told the court.
"He made several references that I was a dead man and to get out of the country ... He went for me in the doorway. I thought he was trying to get into the house. I pushed him back. We rolled about the garden. He kept saying 'you're dead'", added Mr Frazer.
He continued: "I felt threatened given I had been under so many threats. I was very concerned. Someone coming in broad daylight and doing that is very worrying."
Mr Frazer added that he believed McGirr was there "on behalf of Tyrone Provisional IRA" to threaten him.
Defence lawyer Liam McStay told the court that McGirr had genuinely believed Mr Frazer, who has cancer, had died and he was delivering a sympathy card to his home.
He claimed that Mr Frazer became aggressive towards McGirr, wrongly believing he was a threat.
"My client had been told that you had passed away. He came with a sympathy card and said 'I thought you were dead'. He shook your hand. You pushed him off the property. You pushed him on the ground. He didn't hit you in any way," Mr McStay said.
" You immediately jumped to the conclusion that this man was hostile to you and he wasn't.
"When my client genuinely came to your house you jumped to the conclusion that he posed you a threat," he added.
Mr Frazer responded: "I have been attacked many times. I know when I am under threat.
"I have a thing from the Secretary of State saying that I am going to be attacked.
"There are well-known terrorists out there who have openly threatened me. I had 46 calls on my phone last week which were threats. I have better things to do than be in this court."
The court also heard that McGirr has neurological and psychological problems stemming from a brain injury and "intent" could have been lacking at the time of the incident.
The case has been adjourned until 10 February to hear from a police witness.