Sounds like speculation wrapped up to seem like a story. It wasn't a surprise that Leave won as it was marginally ahead in the polls.
I didn't know Farage suggested otherwise or what he knew when he said it. He wasn't leading the Brexit campaign once the formal process began.
Bear in mind there's a major campaign by the EU to disqualify Brexit as the EU is a mess right now and domino-exiting a failing organisation is appealing. Especially because Merkel is doing the same sort of thing re immigration: opening the spigot too wide in a way that impacts other countries in the EU. For reference, see what is happening in Italy.
More than Putin, Merkel made Brexit happen. We fought two wars not to be run from Berlin. But for some reason the Germans cannot help themselves in any format. It's always a European empire. It's that imperial idea which causes European wars.