holding the door

so this morning as i reached the entrance to work, where we have to input a code to gain acess, there is a woman about 10-15 yards in front of me, and as she is putting in the code she see's me coming.

once shes done, she opens the door, steps in and waits, holding the door. but evidently i am taking too long.....so afte a few moments, just as a i reach the door, she goes, letting it slam in my face.

now what i dont get here is, clearly she thought it was good manners to hold the door and had enough patience to hold it for a few moments, but surely its much much wosrse to actually taunt someone and then let it shut anyway!

i wonder what the world is coming to these days.