Well, imagine we're not talking about the Bible, but some fantasy novel. I assumed that within that kind of a fictional context, there would be a big difference between a real prophet and the usual religious kooks, and the recognition of that difference would be at least somewhat contagious to people who haven't witnessed it themselves.

But I suppose you're right, I was being at least a little too generous. Interpreting that quote in terms of rational ability to respond to evidence was an entertaining stretch, but in the end it's still a stretch.