After reviewing your response, my brother has a pretty good idea of what's going on. He hasn't actually read up too much on astral projection, so it was pretty enlightening. The first OOBE was actually unintentional, and maybe circumstantial as he went 36 hours without sleep or eating too much and filling up on caffeine. The second OOBE was intentional, and was his first attempt he's made in quite some time; I suppose he's just a natural. He now knows to take things slow and keep them short your first few times out as Robert recommends. He's also relieved to here it's natural in a lot of people, he was worried he broke something in himself!

Thanks for the feedback.