No one had been able to find Umbridge since the incident. The attack apparently happened so quickly that there wasn't time to catch her before she ran out the exit. It all sounded so chaotic. Many of the witnesses were afraid that there was some sort of Resistance attack. Thanks to Albert Runcorn's well-oiled propaganda machine, there was a large number of people within their society who lived in perpetual fear that violence was only ever seconds away. When the stunner struck Hermione and she went crashing to the marble floor, the screams and running began. The horrible woman in the ghastly pink robes was able to escape.