I've been to kerela, there I saw a demo of kalladi (ancient Indian Martial Art) and trust me they people are like made of rubber.. they can fold their bodies like anything... so its pretty much possible...
I've seen some pretty cool demonstrations by yogis and martial arts master as well, they are very impressive in skill and flexability.
Its like him folding himself up to be put into a luggage. One thing I do know is that those yoga freaks can do those moves.