गूफ़

At the house it is always dark (night-time) but when Helen and Jim rush from the pub to the house there is daylight.

When Amanda walks out the door into the yard she is frightened by clothing which hits her in the face from a spinning clothesline. In a subsequent shot we see the back door & clothesline positions in relation to each other. It would be highly unlikely and next to impossible that somebody exiting the door would not notice the white clothes on a spinning clothesline and avoid them instead of walking into the path of the clothes.