I suppose it's possible, though I don't think anyone has debunked him 100% yet.
It's very difficult to debunk a testimonial sort of story where someone claims amazing secretive things that they witnessed or were a part of, yet he hasn't proved his claims either so I think it's sort of up in the air and probably only a small amount of people know what really happened there.

Here's a link to the video I mentioned where Bob's credibility is seriously questioned though if you'd like to check it out.