I’m not sure what exactly to call this- I had another GW2 user visit the place with me to make sure it wasn’t just happening on my screen (and its not). I figured I’d post a screenshot of it? I don’t think there’s anything that can be exploited about it, but better safe than sorry. :P
Screenshots:
http://oi43.tinypic.com/2na7k48.jpg (entrance to bugged area straight ahead)
http://oi39.tinypic.com/2j0ku52.jpg (rendering (?) error?)
http://oi39.tinypic.com/jpv52g.jpg (through the vault door in the bugged area)