i heard that you end up in some infinite stairwell? but i can't trigger this ending either so i'm not 100% sure
it basically is that. I got the ending and all it does in ending 14 is give you a fire escape and if you click it the screen goes black and you hear running. I think it might be a reference to the fire escape you see in ending 1 after the protag admits he needs the job and a fire escape door opens to reveal the inside of the elevator