Okay, the lady went nuts. It happens. The drive-up window is blood-smeared and shattered; the worker likely shaken and wondering if it's too late to enroll in x-ray tech courses at the local community college. The best thing occurs at the end of the video when the next car in line pulls up like nothing happened. "Hey, does this mean my Sausage McMuffin isn't ready?"
The kicker is that he probably got it with no delay. Ya gotta love McDonald's.