paradoxical
The mirror in the tower was a movie thing, but it's always possible it was something like that. (Personally I think it was rather clever.) Anyways, I agree with the fact that the passageway might've had something to do with it.
I think the passageway helped the baudelaire parents to escape. The Sniket file did have evidence pointing to that... Plus, that's how Quigley survived. He was hidden in an underground passage.