When Killy/Susan gets shot by the random hunter guy, raindrops appear and disappear from the camera lens.
At about 1h, Ben vomits and it dribbles down his beard. In the next shot, the vomitus is gone and his beard's perfectly clean.
When Stephen and Ben steal the car with the 'Ferrari' keys, they stop to get fuel. In the first part of the scene, they refer to fuel as "gas" and themselves being at a "gas station". But later on in the same scene, they refer to fuel as "petrol".
When the 'blue monster' runs into the Canadian's house and kills them, Ben and Stephen jump into the car to get away. A cameraman's reflection can be seen in the car window as they pull off.