Originally Posted by
reft
More than odd. More like illegal if it were in fact true.
The daily closing of an airline lounge may have a different process, but generally just because a place is closed to the public does not mean staff is not still inside. A restaurant or bar will close at some time and lock the doors, and staff will be cleaning the place, closing the cash register and so forth for maybe another hour.
Typically emergency doors require that you depress the bar for 15 seconds before they open, but there are signs on each door saying so. Or there will be a "break glass" or pull handle or another device...