Which... is actually most likely. A couple of times I've fallen asleep and still had knowledge of my surroundings -- I could tell what was a dream and what wasn't, and feel when my limbs were getting numb (Normally in sleep you'd move them, but I had to move them in this state. I also wasn't very happy to because that just wrests you out of the experience), but also feel when I stopped breathing (And spend a couple of minutes wresting myself awake in terror...).
What would make that explanation a 'real' explanation, exactly? If it is an actual out of body experience, what evidence would you expect from that? The most science will be able to tell us -- at best -- is that they noticed a change in so and so part of the brain or that our brainwaves go a little fuzzy, and oh, when we stimulate such and such part of the brain with a small electrical current we can duplicate the exact process.
To which people would just say that, while that is interesting and all, the ability to provoke it with electricity doesn't prove that it isn't an actual out of body experience (Of course, if we can do that, we can check for parity between what the subject experienced and what was actually happening -- but this will probably be met with limited success because they will probably ignore the fact that the brain can hear the surroundings...)