I cringed when I saw "informal survey," but this seems to be in the important bit -

"In most cases, the scam began through Facebook and ended when “Gary Jones” gained access to the victim’s email account."

Unfortunately it doesn't make a lot of sense without context that I can't fine in the article. Was it phishing?

Sadly it's not very clear, and it wasn't a random representative sampling, but it's the closest thing we have to any actual figures right now (AFAIK)