As Buffy is walking home, she is clearly wearing platforms, but later when she goes down to get dinner plates, she is wearing high heels.
As the zombies bust through the front door of Buffy's house, you can readily see that it is a break-away door barely an eighth of an inch thick.
In the last scene before Willow and Buffy are talking in the café, the first shot shows a stream of cars going down the main street. However, on the left hand side of the screen it appears that the cars are coming from a prop wall.
As Giles is driving from the school to Buffy's house, we see him on Main Street, passing the Espresso Pump. Moments later, when he hits the zombie, he has mysteriously reversed course and is once again passing the Espresso Pump, only this time in the opposite direction.