He had nothing to say to Johnston, and if he were to see him in person he would likely be moved to violence, he said.
"If I saw him face to face there would be nothing left of him. That sort of thing goes through your head all the time, every day."
The man entered into what turned out to be a phoney business deal with Johnston, along with a couple of friends.
Johnston said he was starting up a business installing electronic equipment, and that the money his victims put in would be returned to them with a 20 per cent mark up.
But as he failed to make payments, the victims became suspicious. The horrible truth was revealed in late 2017 - Johnston had never intended to start up a business, but had instead been taking the money and gambling with it.
The victim thought there was "no way anything could go wrong", and has been left devastated.
"It's just destroyed me."
He has suffered both mental and physically since the offending - getting ulcers and having to go on anti-depressants.
"I'm just more upset about it day by day," said the man, who lives in Australia and had saved up much of his money through working in the mines and the construction industry.
"Sixty-five years old and I've lost $1.4 million," he said.
"I don't know if I'll get the money back. I will never see $1.4 million.
"You don't recover from that unless you win the lottery."
The man will make an attempt to recoup his losses in a civil case following the sentencing.
He said the feeling of realising the money had been gambled away and lost was indescribable.
"It's horrific, and your life changes in an instant. It's devastating, you can't even explain it. All that money gone. You can't imagine mentally how you'll feel after that."
Commission for Financial Capability's fraud education manager Bronwyn Groot said victims of fraud can suffer depression or PTSD, and that the loss of a large amount of money would exacerbate possible feelings of shame or stupidity.
"It then starts affecting family members as well," she said.
"The blame will go back on the victim, instead of going on to the offender."
She said anyone thinking of investing in a similar situation needed to "do lots and lots and lots of homework" and not put all of their eggs in one basket.
Anyone putting money in should seek legal advice first.
"With any sort of investment, do due diligence and I mean dig and dig and dig. Don't just rely on the words of another party. Don't rely just on a website or an email address."
Fraud victims wanting advice on how to cope with the mental and emotional consequences of offending can head to the Commission's website.
