The ORD AC is one of the few ACs I know of where they don't hold your boarding pass when they give you a shower key. In fact, don't they walk you over to the shower room and then put some sort of sign on the door to indicate it is in use? And since there are dedicated attendants who clean these showers, I find it hard to believe that they would just go home not knowing someone was still using one. I wouldn't be surprised if after the AC closes, they open up all of the shower room doors just as part of a checklist. BTW, what time was this woman's plane scheduled to leave?