"he found he could silently slip in and out unnoticed by pushing his unsophisticated old ID card through a gap between the Yale lock and the door frame"
Makes you wonder about the individuals fitting the door and those fitting any subsequent security device to such a door. I just have to wise up and realise that professional pride has gone the way of common sense and a work ethic.
Work in a largest hospital with various offices locked with those push button combination locks. I also use card through the slot trick. I was caught by a nursey type who wanted demanded in a loud voice "Did you just do what I thought you did?"
"Dunno, shall I do it again to make sure?"
Anyway, if I do come across a door like that, I do show the occupant and suggest that they speak to someone about fixing a piece of wood or something in front of the lock to prevent people like me