"Actually, I had the same thing happen to me once. I went back to the site to find it was a chunk error and blocks did exist. "
You can't fall through a chunk error because it's a server sided calculation where chunk errors are client side. Chunk errors are chunks that weren't loaded client side. Even if you don't see a chunk, it still exists on the server. When you fall into one, the server recognizes that there actually is a block at that coordinate, but that your client is trying to go through the block. The server won't allow that, and will teleport you back repeatedly.
"No, Okie has a point. Even though they are cilent side, if they don't load after awhile, the game may count it as a hole, however reloading the map after death shows it's still there."
Client side events are sent to the server. If they don't match, then the event is discarded. If you fall through a hole in the client, and send a strange position to the server, the server will count it as moving too quickly, or hacking, and you'll be teleported back.