It doesn't seem to be specified in the rules. There was an unguarded passage to the treasury. IMO, this is a bug in the map generator, and you shouldn't exploit bugs.
So, you're saying you can't go to the treasury either? :rolleyes:
I'm saying it's a map bug. Real passages are guarded, but this one is some kind of random, unguarded passage. You shouldn't use it.
In any case, since this issue has arisen, players should pay attention to this bug in the future, and, if they encounter it, resolve the disputed situation among themselves (whether to enter the treasury, not enter, or replay the map).
Charity suffereth long, and is kind; charity envieth not; charity vaunteth not itself, is not puffed up,
Doth not behave itself unseemly, seeketh not her own, is not easily provoked, thinketh no evil;
Rejoiceth not in iniquity, but rejoiceth in the truth;
Beareth all things, believeth all things, hopeth all things, endureth all things. Charity never faileth...