At about 10:00, Amy is frying something; when the scene starts, she's using tongs but for the rest of the scene, she's using a spatula.
The movie appears to take place in upstate New York (license plates on cars are New York state, as well as some other American references); however, around 21:30 when Maria walks across the road, you can clearly see her walking toward a Canada Post mailbox with a University of Manitoba sign above it.
When she strikes Sean on the head with a bottle, there is no blood on it afterward, despite blood pooling around his head when he falls to the floor.