I suspect that he fell victim to a psychological trap known as the Dunning–Kruger effect. It is a case where a person knows so little about a subject that they have no way of knowing how much they don't know.
http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
Thank you for mentioning the Dunning–Kruger effect. I've noted it before with noob hikers. Now I have a name for it.
HJ