I will admit that I don't know much about English law. I am generally familiar with how US courts work, and the basis of a lot of our law can be found in English common law.
The big issue here is did he really commit fraud. In US Courts the truth is an absolute defense. If he committed fraud, they didn't slander him when they said he committed fraud. It I was representing the plaintiff the first questions I'd ask would be "Were the police called? What proof do you have that there was fraud? If you did not call the police, why not? Did the victim of the fraud call the police, or sue for damages?"
This could be an interesting one to watch, if the DF'd him on the heresay of a couple of other people, he may have a case.