I think there's probably something to the UFO phenomenon. However I'm convinced Bob Lazar is a fraud. It's a tricky case because certain parts of his story are verifiable, like that he worked at Los Alamos and that his friends did see a moving light in the sky. The best explanation I've seen is here:

http://www.otherhand.org/home-page/area-51-and-other-strange...

http://www.otherhand.org/home-page/area-51-and-other-strange...

The explanation is he worked on particle accelerators as a mechanic (not a physicist), and they were shooting particle beams into the sky. However since this is all likely classified he would be forced to stick to his UFO story.