He may not be lying. I think he believed he had an experience.
But that doesn't mean it really was what he believed.
This is a 'god of the gaps' moment. He had this experience, which he cannot explain with whatever knowledge he has, nor can he find an explaination from others. The next logical thought process leads to the belief that obviously means it was otherworldly.
From this standpoint I don't think he's crazy, just mistaken. But if he starts saying he's a prophet...