The pensioner was convinced she would be able to pay back the money.
But once McEwan started asking a few more questions it became clear there was no way she could pay back the loan.
Gaining the woman's trust he says she began to mention she had met a friend and this person was going to pay the loan back in three to four months.
"She wasn't that forthcoming about her friend."
But eventually she did admit she had met him online.
It turned out the woman had used an online dating site aimed at widowers where she "met" a man who befriended her online and their virtual relationship blossomed over the months that followed.
The man had conjured up a variety of reasons why he needed her money and she had duly emptied her account over the course of five months through 12 financial transactions, taking a total of $567,000.
McEwan said he got in touch with her bank and the Banking Ombudsman as well as the woman's solicitor which also became very concerned about her situation.
The ombudsman referred him to fraud education officer Bronwyn Groot at the Commission for Financial Capability who helped convince the woman she had fallen for a romance scam.
McEwan, who had never come across a scam in his career, said the biggest challenge was trying to get people in this situation to understand they had been scammed because they thought they were in love.
"In my industry we do come across people who want to borrow money for various reasons. But this is the first time I have come across it."
He said it was not often people borrowed money for scams. Scammers usually just target people with money.
"This person had lost it all and was trying to borrow more."
"When you see someone of this particular age go through this - it is not very nice to see."
He said the situation had made him pay a lot more attention to the statistics around scams and the amount of money lost.
"You work your whole life to get to that point and it can ben taken away in a matter of months."
He urged others involved in the finance industry to be vigilant.
"I would like to think most people would do the same thing."
He said all lenders needed to question why a person wanted the money.
"No one should lending the money without asking what it is for. But unfortunately there are places that will do that."
"There was no way this person was going to be able to repay it. It didn't take a rocket scientist."