I used to work for a financial org, it had security doors to the computer building, it then had double security doors to reach the server room which had a secure "airlock" entry
the only problem was this same computer room had a fire door to the ajoining loading bay ( a bay that was open to all most of the day) this fire door was unalarmed and secured by cheap (and often faulty) mag lock.
to cap this, the server room had its own toilet ( a minor wtf in its own right) the loading bay staff new this and would often let visiting delivery drivers use it (one door as opposed to 3 that need security cards to open)
so it was easier to access the room via the loading bay than the though all the security.
Talk about being more worried about staff than outsiders!