
Other mistake: When Gomez begins to flip through his desk calendar, we see that "today" is Thursday, March 28, 1991. He then turns to the date of the "next quarter". The left hand page shows Thursday, August 8, but the right hand page shows Tuesday, September 9. (00:11:15)
Answer: No doubt the Addams house had one of many secret, confusing passageways to get to the higher floors (and other parts of the house) from the vault that the viewer obviously is not privy to.
Scott215