The day after Donald Trump's vast 1 billion golf resort overcame its first obstacle, receiving planning permission from the local planning committee, Mr Forbes was unrepentant.
"Nothing's changed," he insisted. "I've said from the start that I'd never sell, and Mr Trump knows that."
The truculence exhibited by the 55-year-old smallholder and salmon fisherman is winning him supporters. Mail from around the world arrives daily to his battered home in Balmedie, Aberdeenshire.
There, generations of his family have resided quietly on the unkempt 23-acre site. Though unsightly in the eyes of some, the place attracts little attention. But because it lies between the two championship golf courses planned by Mr Trump, his humble home has become a cause clbre.
Since turning down a 350,000 offer to buy his land and the offer of a job as a handyman on a reputed 50,000 a year, Mr Forbes's resolve has strengthened.
He vowed yesterday to donate his house to a cat and dog home before he would let Mr Trump take it over. He added: "I'll be opening up my own nature reserve next year to help save our wildlife being driven away.
"It's time they realised they are now dealing with thrawn Scots. We're just starting our fight now. They had better watch out."
That stance has frustrated Mr Trump's representatives. Given he had every reason to celebrate the councillors' decision, George Soriel, head of international development at Mr Trump's company, was in bullish form when asked about Mr Forbes.
He said: "We've planned and designed around him. He's a good man who's playing a smart game, and I wish him the best of luck. He can stay there."
On whether Mr Trump would be content to have the farm in the vicinity of his development, Mr Soriel added: "We'd rather have him clean it up, but at this point, we've no interest in purchasing his property any more. I'm assuming he's been a fairly good neighbour, and we'll be a good neighbour to him."
Yet Mr Forbes is not the sole voice of opposition to the development. One group fighting the resort yesterday vowed to "go all the way" to stop the scheme.
Donald Milne, of Sustainable Aberdeenshire, said: "The fight goes on. We're not finished yet."
Meanwhile, Mr Trump insisted the resort will be of environmental benefit to the area.
He said: "We really look to do a beautiful job. It's very important I do something that's environmentally sensitive."