In a phone call Samantha Stobbart told the 37-year-old she was seeing her new boyfriend that night, that she had a new hair-do for the date and asked if he was jealous about it, Anthony Wright told the hearing at Newcastle Crown Court.
Coroner David Mitford asked: “Was she deliberately trying to wind him up?”
Mr Wright, who knew Moat for 14 years from working as doormen together in Newcastle, replied: “Oh yes, without a shadow of a doubt.”
Moat had heard while in prison that his relationship with Ms Stobbart was over, and she had told him her new man was younger and could knock him out.
Mr Wright told the hearing: “It was almost inevitable that when he got out of prison he was going to look for a straightener with this man.
“If you knew Raoul it was like a red rag to a bull. I couldn’t work out why she was saying it.”
Moat rang his friend hours later, after he had shot dead 29-year-old Chris Brown in Birtley, Gateshead, and saw Ms Stobbart crawl away after being blasted in the body, and told him “I have done them”.
Mr Wright said: “He was calm. I would have expected someone to be more panicky.”
Moat told him he had two cartridges left and was undecided whether to kill himself or take on the police, the jury heard.
In fact, he had more ammunition and the next day shot unarmed Pc David Rathband west of Newcastle.
When Moat was cornered in Rothbury, Northumberland, six days later, Mr Wright, who owns a garage and lives in Ponteland, was quickly driven by police to the scene.
He donned a helmet and bullet-proof vest and was taken to within 100 metres of where his friend was surrounded by armed police but he did not get to speak to Moat.
Mr Wright questioned why he was not allowed to make contact and said his friend was obsessive about girlfriends and could not handle rejection.
Earlier, Angus Moat, who shares the same mother but has a different father to Raoul Moat, told the inquest he pleaded with police to be allowed to speak to him on the night.
He wanted to tell the former nightclub doorman to surrender for the sake of his children, and that there were people who loved him.
The tax officer, 41, knew Moat had read reports in which his mother had claimed he would be “better off dead”, and said he wanted to persuade the fugitive a life sentence would be “better than death”.
Mr Moat said their mother suffered from a bi-polar disorder which led to psychotic episodes and that she was emotionally abusive to her sons.
The inquest heard Moat had said he would “take the shoot-out” rather than go back to jail.
The vow was recorded by the gunman on a dictation recorder three or four days before he was cornered by police marksmen.
In the message, he described losing the only two people who mattered to him, his grandmother and Ms Stobbart.
He said: “If I went to jail now, I could hack it because I have lost everything and I have nothing to come out to.
“I have come out and got my vengeance. I have set Sam up for life, financially at least. But it is not really what I want. It would be a waste of a life and a waste of the taxpayers’ money.
“Just take the shoot-out and everybody’s happy.”
Supt Jim Napier, the Northumbria Police officer in charge of the criminal investigation into Moat’s rampage, said the message had affected the way in which the stand-off was handled.“It is a personal disappointment I never got to see Mr Moat account for his crimes,” he told the hearing.
Jurors heard the former nightclub doorman attempted suicide in 1999, when he was admitted to Newcastle’s Royal Victoria Infirmary after taking an overdose of the clubland drug GHB. The hearing continues.
The hearing was adjourned until tomorrow.